Hi:)
 
Another suggestion:
 
Normally I do every note manually, sometimes loop it, change very often velocities (Hi-Hats especially), then humanize them.
 
But sometimes I play them with a pad and a drumstick at 50 to 70 % of the origin tempo, I know I have a much better timing (feel) if I play it slower! (I'm not a drummer, but bass player).
I start with playing the melody and the structure of the song (Verse, Chorus, Solo a.s.o) 
Then the Mididrums with a pad. Turn it to normal tempo and then the bass, guitars.... 
 
Bassman.
 

jerrydf
Every note by hand. Start off with a copy/pasted pattern but revise that note by note as the track develops.
Attention to dynamics, especially those almost inaudible snare notes on shuffled rhythms.
Make sure each pattern would be playable buy a human drummer.
Things like triplets are rarely exactly on time...  a real drummer speeds them up a bit...  make sure the hi hat isn't still going during fills. Would a real drummer really get his hand from that floor tom to that cymbal in that time?
Make sure each kit piece is the sound you want...

 
I agree 100%. I would also suggest that it is generally a good idea to emphasize the on beats and de-emphasize the off beats. This applies at not only at beat level, but also at half-beat level, quarter-beat level and so on. Only emphasize a particular off-beat if the other instruments are also emphasizing it.

Find a song that's very close in feel to the one you're working on and analyse what the drummer's doing. You might be surprised at the space drummers leave in certain places, it's a common mistake to keep the drums firing away right through a song.
 
The only time I got close to 'realistic' was doing a cover song and copying every drum part and fill by hand. Very laborious stuff. Nowadays I'd rather find a drummer online to work with.

Hidden_Symmetry
Dynamics & time.
 
-You can take a heavily quantized loop & by varying it's velocities change it's feel.
-Try selecting just the individual parts in either sections or the whole tune (hats, kicks, snrs, cymbols, toms) & slide them + or -  a certain amount of ticks from one or each other. It can drive, push or lay-back the groove with the other tracks in your project
- Hire a real drummer

jamesg1213
Find a song that's very close in feel to the one you're working on and analyse what the drummer's doing. You might be surprised at the space drummers leave in certain places, it's a common mistake to keep the drums firing away right through a song.
 
The only time I got close to 'realistic' was doing a cover song and copying every drum part and fill by hand. Very laborious stuff. Nowadays I'd rather find a drummer online to work with.

Both Hidden_Symmetry & jamesg1213 are correct.
 
The key thing is to think like a drummer. 
 
I spent years analysing what drummers were doing and imaging myself playing the parts. When I eventually got an electronic kit, it was just a matter of getting used to the limb co-ordination.
 
However as Hidden_Symmetry said, dynamics is a big part of it. In particular, the velocity curves of you particular drum samples can have a huge effect here to making it sound realistic... especially if the MIDI loops you're using weren't created using the same drum vsti.
 
One thing I've learned (only quite recently to be honest), is that its a mistake to go for higher velocities to make things like the snare cut through. A real drummer wouldn't hammer the drums at full velocity all the time (unless perhaps it's punk or thrash metal). But this is the major reason lots of MIDI drum parts sound like machine guns.
 
Keeping things at a lower velocities gives you a much better dynamic feel... and you can always use compression and saturation to add punch at mix time.
 
As far as timing is concerned, I find this largely down to taste as to whether you want things "in the pocket", or going for a pushed or laid back feel. Heavily quantised drums though, will sound artificial.
 
For years I quantised everything as on my Amiga the timing was never that exact anyhow, so anything other than exactly on the beat just sounded out of time. Nowadays I tend to be more selective: hi-hats I leave alone, whereas kicks & snares I'll be more strict with quantisation on the 1st & 3rd beats, but less so elsewhere.
 
In saying that, in my experience, the notes & dynamics are far more important than timing for realism.
 

I play a lot of different instruments and have dabbled around on drums. I do not call myself a drummer. But, I had the privilege to play alongside of some really great drummers. Playing rhythm guitar made me very conscious of how and where to lock in to the groove and these are the main things I do to sound as authentic as possible when programming drums.
1. Drummers ALWAYS subconsciously hit the cymbal hand harder on the downbeat!
2. Time adjust the snare on slow songs just a tad behind the accurate down beat for a relaxed feel. Usually during verses.
3. Time adjust the snare on fast songs a tad before the accurate down beat for a more tension feel. Creates a little more excitement!!
4. Ghost notes on the snare during grooves are really important.
5. No drummer I have ever watched so closely has ever played the exact same pattern over and over on the cymbal hand!!! Always randomly change the cymbal pattern every couple of measures or so. If it's an 8th note pattern, add some sixteenth notes randomly in the measure. Overtime you will find the spots to do this. If it's sixteenth note patterns, take out some cymbal strikes here and there.
6. Even with Factory played midis, ALWAYS reduce the velocity of the entire clip another 5 to 10 per cent and edit the velocities for the accents back up 5 or 10 per cent for more pronounced dynamics.
7. Always randomize velocities for each hand and foot!!!

I teach my students this simple philosophy. Notes are the voice singing. Rests are the breath between the notes. But dynamics is the pure soul of the music.
I hope some of this helps you. I do not profess to know everything about drums but I do think these crucial things that I have covered are the meat and potatoes of programming interesting drum tracks.
Good luck!

There are so many ways to do this that not one thing will work for everyone, that's the great thing about threads like this, you see how each and every one of us work differently but still reaching for the same goal.
 
I start all my track from scratch. I used to be a button pusher back in the old days when I used a drum machine.
But even early on I realized that writing my own beats from scratch set them apart from a preset (even a preset that has been customized to taste).
 
I will typically start with a 4/4 drum beat (Kick on 1, Snare on 2, exc) then play riff ideas and link them together.
Then I will go back and delete it and start over from scratch.
 
The mixing process is a bit different, For drum sims, I do a lot of sound stacking.
This is essential for me with rock and pop as I have 3 kick layers (one for thud, one for pop, another for crack)
Snare is done in a similar manner. Toms are bused to FX.
 
This is how I achieve drum edits from scratch.

Jamstix. Big learning curve but when done right it can make AD or Superior sound legit.

You can use AD2 to humanize your drums.
 
You can import your drum midi files into AD2, transform them, and bring them back to your DAW.
 
It's pretty easy:
 
https://www.youtube.com/watch?v=jg0NklSRlWY
 
Hope this helps

WOW, great thread!!!  Big thanks to all the contributors!  This forum rocks!
 
Thanks,
Kz

I'm in a pretty similar style of music, and also use MIDI drums.
I USED to pore over every note by hand, and got quite realistic.  A little while ago, i realized a better plan:  Now i'll take a pre-made loop that sounds realistic (usually a real drummer that's created it, like Superior Drummer's stock) and similar to what i want, but then drag the hits to the places I want them and do any large-scale overall velocity changes on a particular drum.  And do any minor tweaking to polish.
This way, I get the human rhythm and velocity variation of having a real player, but playing the actually sequence that I want.