Cold Natured 800 Intruder

As water-cooled twins, VS800s are just sort of cold blooded by design, as it takes a while for the motor to warm up with all that cold water in it- not much you can do about it.
Make sure the choke is adjusted correctly, and use it correctly. It should stay anyplace you put it, not just all the way out or all the way in. If it doesn't, grab the black rubber grommet around the choke knob shaft and turn it clockwise as tight as you can, which will increase the drag on the choke and make it stay put. Pull the choke out all the way to start the beast, then push it in until it idles without racing too badly. You can go ahead a drive with the choke part way out, and then push it in as the bike warms up, or when you get to the open road and need full throttle, whichever comes first.
You will appreciate the water cooling in the summer heat though, so it is worth putting up with the cold-blooded nature of the bike.

Engine RPM should increase when you pull the choke out. If it does not, your choke cable is either broken, detatched, or very badly out of adjustment.
My VS800 has always been cold blooded, as even on a 100 degree day it needs to warm up for 30 seconds or so before I drive it, but even on the coldest days about 3 minutes is enough warm up time for it to drive smoothly.