wow I love equally the varying amounts of details in each "sketch". You can't really call them sketches... Probably my favorite is the middle one cause I LOVE sci fi. You should definitely work on these more!
Just out of interest, how many hours a day do you put in? and do you not get wrist pain because I find after a few hours I'm hurting pretty bad. Either way these look great, nice and warm and saturated colours.
Well I usually draw 6 hours per day at work, and 2 hours at home = 8 hours No-no, I dont feel any pain after a work-day Maybe its because I love sports and my wrists and arms are quite strong. Probably you should start to train and massage your arms The good way to get your wrists stronger is an expander Sorry for my bad English