In Colorado Springs I25 is the main interstate and is best for north and south. Your best chance for a ride to Denver is probably Uintah. It is a fairly main road on the north side of down town. If you are headed south try Bijou bridge as it is the main on ramp into down town. These are pretty interchangable as there are quite a few exits through C Springs and there is alot of local traffic. But I have had Luck at just about every exit from the south side all the way to Glen eagle.
If you are headed east it would probably be better to head to Denver first but Highway 24 that runs through down town is a good option. West on 24 is probably the easiest hitch around, and it is very beautiful and there is plenty of camping along the way i.e. 11 mile and Rampart range.
Colorado Highway 115 south to Penrose is a difficult hitch, but is doable. Standing on the side of the highway before the speed limit picks up just south of the 24 at the intersection of 115 and Cheyenne Road is a good place to catch a ride, but most of them aren't going long distance. Your best bet to catch a ride to Penrose is from the entrance ramp of 115 and South Academy Blvd. Because this is a difficult hitch, another strategy would be to just start walking backward down the 115 with your thumb facing traffic.