I use "Clean Edge" masking tape from the paint shop, similar to masking tape. But has less adhesive and does not bleed when cut hence the name clean edge. Also comes in sizes from 1/2" to 1 1/2"
I bought some Painter's Mate Precision green tape. It's a darker green and a smoother finish - not that crepe look that the standard green or blue stuff has. It has worked great, no seeping even when cut, but I'm pretty much out and you think I can find it ANYWHERE now? Nope. I even ask for it at General Paint, Benjamin Moore, etc and they have no idea wtf I am talking about. I really hope the electrical tape works.