Covering is a blast, glad to hear you're using Ultracote. Start at the tail and work your way forward on the fuselage. Take your time and set goals. Do the stab one night, fin on the next night type of thing, never rushed and always enjoying. Do the bottoms of the stab and the wings first then the top. Make sure you have a good heat gun. When covering the wing leave about 2 inches of overhang all the way around. Using a medium heat iron, tack the covering in places around the wing pulling tight as you go. Then turn the heat up and adhere the parameter all the way, tight. Pull out the heat gun and tighten the covering on the entire wing. Use your iron, with a sock, and go over the edges again, the balsa sheeting, cap strips etc. I usually cut the TE halfway through back edge then when I cover the top I overlap and trim flush with the sheeting. LE, I cut past center then trim the top covering to overlap past and slightly back under. For the edges, cut the overhang in strips, fairly wide strips where its flat but as you approach the LE cut the strips closer together, don't cut all the way to the wood, leave about a 1/4 inch. Now just using your iron pull each "tab" and iron it down. Once finished take your knife and cut the covering "flaps" off about 3/16 of an inch , 1/16 of an inch iside your cut, leaving a clean 3/16 tacked edge all the way around. Cover the bottom, do the edge, cover the top do the edge. Now you can just iron on a cap over the entire tip and then trim around. When I seal the firewall, I usually paint the thinned epoxy around the top and bottom edges of the engine compartment. This helps attaching the covering, I believe it helps to hold it on
When you have to cut any holes in the covering, wing tubes, wiring, alignment pins etc use a hot soldering iron. It cuts the holes and seals the covering to the edges all at the same time. I also recommend that you seal your control suface hinges. I do both sides of each surface myself.
Looking forward to seeing your SE
Hope this helps a little!