I find (and I'm not a finger picker...)
 
That in certain styles of strumming, you get a much better, more relaxed natural sound/feel when playing the guitar with your nails on the right hand. With the backs of the 1st, 2nd, and 3rd fingers on the down stroke, and the back of the thumb on the upstroke. To do so your nails must be well maintained and at a proper length. But I find for strumming (some songs) this tech works much better than a pick. It became obvious on one I'm working on because it's very difficult to strum it with the pick. But when I use the afore mentioned finger strumming technique, it fits perfectly. 

I stopped using a pick years ago, cos I kept dropping it I noticed Mark Knopfler doing a sort of hybrid grabbing/picking technique and thought I'd give it a try. Just stuck after that and now I very rarely pick up a pick. Learned how to do pinched harmonics with a weird little inversion of my index fingernail.

there are so many ways to play the guitar... part of the fun I think!
 
For plain old strumming I use a pick most of the time, and for flat-picking, well, it is part of the sound<G>. But sometimes I don't have a pick handy, or I just feel like shaking things up a bit, and will play with just fingernails.
 
For fingerstyle I very seldom use picks, although for certain styles a thumb pick adds some oomph to the bass strings, and I like that sound. I had to learn to use finger picks for pedal steel (again it's that sound) and I really struggled until I found these picks with a cutout (Propik from Fingertone) and now I can use them without hating it entirely. I've used them for fingerstyle from time to time as well, but I have to really work at it.

For slide it has to be bare fingers, when you lose the contact with the strings in the left hand I find that I need to get it back in the right hand.

Just one of the reasons I love playing guitar!

Back in college I studied classical guitar so I always had the precisely filed nails. But that was 25 years ago. Nowadays I just keep them trimmed, or use the finger picks for lap steel, resonator or banjo. I also use regular old flat picks. I guess it depends on the style/feel or mood you're trying to create.

That's exactly how I strum with the nails. You can get a real flamenco style thing going on.

Back when I played classical seriously I had the full on nails. I was obsessed. I filed them to an upward slope going left to right, which really makes the strings glide across them smoothly and makes for a great tone. I took more care of my nails than the average woman. I had the multi-surface nail files with the 4 grits, rough to smooth. Every day I would use all 4 grits then finish off with a piece of cardboard to get that final shine (it really works). The feel of pristine nail against nylon string is worth it.

And I also used a clear lacquer for a layer of protection. I guess a guy can get away with that in New York....

Ultimately though I got sick of breaking them when I switched to steel string (0.14's). So for a while I played steel string with metal fingerpicks, and I loved the tone, but I got through strings way too quickly.

For years I played lead with thumb and index finger - you can get a really impressive picking speed if you stick at it. These days I've gotten back into playing with a pick after having never used one for 20 years. It feels great!

I prefer the flat pick.
 
I've tried the finger picks and never really liked them. My nails are fairly thin and that wouldn't work.
 
A buddy of mine, also with thin nails, even tried eating gelatin to try to grow thicker nails..... I don't recall how that turned out...
 
Quite a few rockers don't use picks.... so ...whatever works best.

Zinc is important if you want strong nails. A frightening number of people are deficient in it.

I've played classical guitar for well over 30 some plus years now.....
 
I use this style on my electric as well as my steel strings instruments.
 
I have tried every single concoction I ever ran across......well at least almost all of them......
 
The only thing that works is to just take care of them ....eat a well balanced diet...take a daily vitamin supplement and that is about all you really can do....cause the nails grow from the inside out and from what you eat and how you take care of yourself..... 
 
you do not need Long ones...or flied to special shapes or eating gelitn etc........(actually the very best shape to file your nails to is "follow the curvatur of your finger tip") keep em short which supports them...the longer they are the more dangerous they are to you and anyone you stab!  kidding!!! 
 
But really when you have short well rounded nails that are filed to the shape of your finger tips they are a bit stronger... the longer the weaker and more fragile.....also do not forget..when you file ....file at a 45 degree angle and then rub the filed edges down with 1200 or 1400 wet dry sand paper...this will buff the edge and give you that glossy tone.....
 
When yo play it is a combination of nail and finger tip flesh not nail alone....so if you are right handed make sure you file really well up and into the left hand corner of the finger tip....round and smooth is the way to go and think....
 
If you are going to play on steel strings then you need to see a nail expert to apply a gel coat over your nails.....this will thicken them up and make them stronger and resist wear......steel strings almost eat up nail surface.....nylon strings are more gentle to them....
 
Yes a top coat finish does help but I never cared for it becasue it does stop the flow of oxygen to the nails. When you go to strip it off with nail polish remover you do weaken the nail....so I tend to stay away from it.....
 
But these would be my recommendations....
Keep em short
keep em well groomed
follow the shape of your finger tip
file at a 45 degree angle
buff the edges with 1200 to 1400 Wet Dry sand paper
Should do it!
 
 
Scary how much I know about this nonsense!!!!!!
Clifford
 

I have always played acoustic with the fingers and pick with electrics. Or a cross between the two. A pick always seemed to harsh for an acoustic, but it's a personal thing. I watch Jeff Beck and I'm grateful that there are no rules.

No rules indeed. I love playing with my nails and the pads of my fingers. Like Clifford, I've found short and shaped to my figertip very comfortable and effective. Several months ago, I shut my thumb in the door of my work van. Even as the colorful expletives were flying, and it was turning a lovely shade of off black, I was thinking of how this was going to affect my playing. Of course the nail fell off, but I'm about 6-8 weeks from a decent edge again. I can't wait.
Anyhow, on the acoustic, nails and pads almost always.
On the electrics, anything goes. It just depends on the mood and the song.
With slide (electric) I prefer a flat pick, but do a lot of palm muting.
I've tried to get used to finger picks with the lap steel, but they make me feel like a cat walking on fly paper. Someday I'll get it.
Whatever works, it's all good.