I used to record bands and had a dedicated monitor mixer and a audio interface with enough outputs to supply the monitor board.  I no longer do that and have a much smaller interface nowadays and normally just bring in singers at this point... I'm the "band".

Therefore I'm setting up my monitor mix by using the sends in Sonar and sending the sends to its' dedicated buss which in turns is an alternate mix I can send thru an additional stereo output of my soundcard.  That way I can muck around while recording and listen to the main/master mix and the talent (usually just a vocalist at this point) can have their own mix. I keep the sends prefader of course.  Soloing etc doesn't affect the "MIX 2" either...since the sends are all before that stuff.

I'm not really seeing any other way to do it, and it also seems pretty simple too.  My latency is low enough that it isn't a problem and I can also use FX from Sonar....like reverb ...and send that to my "MIX 2" as well, should the singer want a touch of it. My soundcard also is a "zero" latency on the recorded input as well.  Only the playback tracks (or FX) would have latency.
So...two simple mixes on record/playback....using sends like you would a "monitor mix" on a live board.   
Typical setup I guess is my question??   ....or am I too old to know a better way?

Sounds ok to me - I use a similar system so it must be right 

As long as the latency is not a problem, then your set up seems hard to beat for simplicity. And it sounds like you're old enough to know that simpler is usually better. 
 
If you're using an audio interface that has a software mixer, you might get even less latency. I'm using RME, and you can get zero latency by going through its TotalMix software.  But then you would have to keep track of the routing in the TotalMix GUI, and TotalMix is - how should I put it gently? - somewhat opaque to human understanding. High quality? Yes. Reliable? Yes. Simple? Fuggetaboutit.
 
Go with simple, unless there's a compelling reason not to.

What I've been using is a little Mackie Mix 8 mixer just for monitoring. I like having the "real" controls at my fingertips. My 6i6 has Mix Control but I find it to slow to set up and then you loose focus on Sonar while tracking. 
 
CH1- Joe Meek 3Q Vocal pre amp has 2 outputs I can split the signal
CH2 - My trusty 505 Drum Machine
CH3- Second mike on my Guitar amp 
CH4- Stereo 3/4 output of my interface 
Then I have my Lexicon MX 200 in the effect loop for reverb if needed.  
 
I use the mixer headphone output and it is WAY better than using the Focusrite. 
If there are 2 people then I just add a Rolls splitter or use the Focusrite as well. 

dupplicateddd

Yeah....ive had a variety of monitor mixers...down to the litttle Mackie HMX-56 (?)...with my smaller setup. But using Sonar I have unlimited sends vs the number of channels on a hardware mixer. So...I sold it being a "hot" item in eBay. Thxs for replies and confirmations

And...not to mention unlimited plugs for fx....should they be desired

mixmkr
I used to record bands and had a dedicated monitor mixer and a audio interface with enough outputs to supply the monitor board.  I no longer do that and have a much smaller interface nowadays and normally just bring in singers at this point... I'm the "band".

Therefore I'm setting up my monitor mix by using the sends in Sonar and sending the sends to its' dedicated buss which in turns is an alternate mix I can send thru an additional stereo output of my soundcard.  That way I can muck around while recording and listen to the main/master mix and the talent (usually just a vocalist at this point) can have their own mix. I keep the sends prefader of course.  Soloing etc doesn't affect the "MIX 2" either...since the sends are all before that stuff.

I'm not really seeing any other way to do it, and it also seems pretty simple too.  My latency is low enough that it isn't a problem and I can also use FX from Sonar....like reverb ...and send that to my "MIX 2" as well, should the singer want a touch of it. My soundcard also is a "zero" latency on the recorded input as well.  Only the playback tracks (or FX) would have latency.
So...two simple mixes on record/playback....using sends like you would a "monitor mix" on a live board.   
Typical setup I guess is my question??   ....or am I too old to know a better way?

This is how we did it with hardware, so it makes perfect sense to this old guy.
But in SONAR, is this how you set it up?
Prefader send ---> new bus ("Headphone Mix") ---> Audio interface ---> headphone jack or amp. (I'm using a Focusrite Scarlett 6i6, which is pretty much like your UR-44.) I'm vague on where I send the headphone bus and where I pick it up in the 6i6.

Not to hi-jack the thread but...
What do you all like on your hd ph mixes?
What do you like to mute?
How does this affect the artist staying in tune/emotion with the song?
I am curious because I usually just lower the whole mix the way it is.

Larry...you got what I do.  The headphone buss is routed to an alternate output on your Scarlett, so you can use your main L/R like you always would for monitoring as desired...and the additional/alternate mix is for headphones.  More headphone mixes would require an additional send>buss>new output on soundcard....  for as many as you'd want.  Typically I just need the one extra mix, recording one track at a time.  Therefore in Sonar, select your headphone(another) output, that is listed for your Scarlett on the dropdown menu for the buss output selections.

Frankjcc...I like what the talent likes.  Sometimes lowering the whole mix makes it difficult to hear precise timing.  So maybe the drums might be left a tad higher???  Some vocalists don't want to hear background vocals ...some do.  I usually take out instruments that might "play around" a vocal line, so as not to stomp on the vocals when recording.
Usually just the basic instruments work best with additional stuff added to preference.