What breed do you have? I only ask as turnout seems to vary massively depending on breed and age. We keep Berrichons and Zwartbles and I wash, card and trim the lambs the same as the adult sheep, but obviously have a lot more wool to work with when creating the desired shape.
You would probably pick up a lot of tips by going to the next show near you that has classes for your breed and watching the competitors preparing their sheep before they go into the ring (but save questions until after the showing has finished as it can get a bit frantic right before!)
Good luck and enjoy it - showing can be a lot of fun and it's really nice to compare stock that you've bred to others to make sure you're going the right way.
Edited to add - our adult sheep don't get shorn early and kept in like some do and we still get pretty ok results so don't discount taking older stock too. In fact, the shearling ram we took to Three Counties came in from the commercial ram field a week before the show to be washed and prepared as the one we were going to take had a fight with a gate and his knee swelled up and the replacement came 4th in his class.