"How do YOU give your artist -or yourself- a headphone mix with reverb?"
 
my answer is:  hardware
I know you said in your original post you don't have hardware to be able to do this, but neither did I before I bought some! 
 
I bought a cheap behringer FX unit for less than $100 and I put it in the track going back to the vocalist.  works great!  I do use a mixer to send a different line to the headphone amp than I do to the soundcard.
 
actually, I split it before the mixer, sending the mic preamp directly to the soundcard, but since my mic pres all have more than 1 output, I use the 2nd output to send to the mixer, where I mix in the vocalists' reverb and the other backing tracks from sonar for them to sing with.
 
hardware - best way to go!  no latency issues that way.

Sacalait I guess you were "fishing" for what others do as your solution seems to be the best if  you have no outboard gear. 
Most of us cannot engage input echo without hearing the Round trip latency delay. I like your solution as it is true we might not notice the delay at that level combined with the reverb.
 
 
Turning the channel fader off is a brilliant solution. Would have never thought of doing that. As we all know, that fader has no bearing on the input level being recorded. 
Not only does it not print to tape, it gives you the reverb send ready to go for playback. This avoids the dreaded full on inserted effects send issue we where just talking about in another thread. 
 

I would add the example I give above is ONLY for the reverb send to the vocalist and I never engage the record button on that track.  I'm recording the vocalist on another track.  The reason I turn the fader off and switch to pre-fader on the reverb send track is to lose the direct signal- yes if it were on latency WOULD be an issue.  It works very well with any of the reverb plugins too!  ...just an FYI.  ...and I'm looking for a used SPX1000...

Well you could record to the same track,, there would be no issues as the reverb is after the fact. The one track method would be identical to your 2 track method. When a tracks input is from your audio interface that track is controlled by the interface parameters only. There is no cross talk ( one would hope) 
I guess the 2 track method would be handy as you insert new tracks for overdubs  and re takes. 
 
If you like the sound of the Yamaha SPX series why not look for a used 01v or any older Yamaha digital board. They go for $300 on E bay. Mostly all that goes wrong is a few channels are not working. One of the main reasons I keep mine is the effects are still as good as I've ever used. And you get 2x the SPX in there. 
 
I use my board for a lot of inputting to Sonar via the SPDIF to my interface. I can use a lite compression and add the reverb to the monitors OR sometimes I've printed the effects. Super easy to use. Super fast headphone cue mixes. Could handle 5 musicians. 
I'm looking to replace it with the new QSC Touch Mix 
http://qsc.com/products/Mixers/Touchmix_Series/TouchMix-16/
 
 

I personally take mine straight from my interface (ZED-R16) and use an external unit for reverb. (Quad 4) Any live input via sends on the desk itself, any tracks from Sonar via a per track send that then goes to a spare channel on the desk and then use a send on that channel to route it to a headphone amp (as per the live input).
 
It can all be done via the software of course using sends but to have a completely separate headphone mix you ultimately need more than one output pair on your interface.
 
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I just did a session with a client and thought I'd give it a whirl. 
All I did was toggle input echo and then turn down the channel fader a bit until the delay was minimal. 
I then cranked up the reverb send on the channel until client was happy. 
Worked fine.   BUT.. 
We needed to over dub a few spots and all went out the window as I had to turn the channel up and the reverb down... 
So the 2 channel method is defiantly the way to go. 
 
But I just went back to using the 01v reverb..was faster in my case. 

I create a stereo bus called "Vocal Reverb" and put a revern plug-in (like Lexicon) in the bus Fx bin.  I use Send on the vocal track(s) to send to the Vocal Reverb bus.  I use however much is appropriate for working and it does not print to the track.  Noramlly, you turn the reverb in the Fx bin up to 100% and then adjust how much reverb you hear with the Send from the vocal track.  I normally leave the Reverb bus at 0 db but I guess there is no real rule about that.
 
When it is time to mix/export, you can keep this setting or change it.
 
By the way, that would be exactly what I would have done in an analog/hardware based studio, except that there would normally be a reverb send/return already set up so you wouldn't have to create a bus.  That said, there were times when all the send/returns were in use, and we had two use two tracks as the stereo return, which would be the same thing conceptually as adding a stereo bus in Sonar.
 
One last thought: I normally use an algorithmic reverb and not a convolution reverb during tracking.  I am not a fan of convolution on most pop vocals, but, even if you are, it takes a lot of CPU and the latency may bother you when recording.
 

Pershing's clever method is just 'too cool for school' and it works for me:)  Thank you!

That`s why I love my yamaha 01v96i,such a small mixer with 16 high quality inputs and unimaginable routing possibilities without any latency issues.
Peace

Sacalait
I don't have a mixing board.  I'm using Sonar only.  This is what I've figured out and it works on reverb- pretty much regardless of what settings you have in the mixing latency (well, at least 1024 or less).

1:  In the master section I insert a stereo bus and drag in a reverb plugin (i LIKE the Lexicon plugin that came with 8.5 and X1!).  Name it "Reverb"
2:  Insert an audio track and insert the Reverb send
3:  On this audio track click input echo to "On", lower the volume all the way to OFF (vital because it eliminates the dry signal), assign the input to the mic you're using on the vocalist, click the reverb to "pre fader", and adjust the send level to taste.

Because this is a reverb effect you wont notice latency.  In fact if you have the audio buffer setting to higher (like 1024) it almost helps because of the pre-delay.  NONE of my artists EVER complain about latency when I do it like this.  I don't think this would work with effects like EQ, compression, or really anything else but reverb but it works nicely to give an ITB reverb mix to the performer.

Anyone else do it this way? 
 

This is exactly how I do it.
 
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