Trading tips for gutting, transferring, and carving the real thing.
Just a quick tip if using electric lighting in your pumpkin - Cut your gutting hole in the bottom of the pumpkin instead of the top then you have more room for design, no light bleeding through the lid edges and you also have an opening to rig your lighting set up through. Also if you remove enough flesh evenly the whole pumpkin glows a fantastic uniform orange :D
I love going in thru the bottom, it really looks nice in my opinion. I also set my pumpkins down on the lights, so things are much easier to light.
I think it's easier to do the pumpkins that way, too. I always seem to get light coming thru the cut if I remove the top. It's less noticeable on the bottom. Having more room for the design is helpful, especially on a longer design.
I hear a lot of people telling me to go through the base, however with how many I light (30) It's not convenient to do it this way. I tend to run around a lot on Halloween re lighting so its simpler (for me) to just do it through the top.

I do like the idea of doing this for one or two though.
I go through the bottom and set the pumpkins on Christmas lights. I had about 160 pumpkins in my display, real and foam, and the only re-lighting I had to do was if a bulb burned out. Here's a photo with part of the display. Search for Ken's Pumpkin Patch on Youtube if you want to see the full display. The white Harry Potter pumpkins are set on LED push lights bought at the dollar store.