I use a Jett refueler (www.jettengineering.com). I've gone to bubbleless tanks on all of my planes now. You'll get much more consistent engine runs and don't have to worry about air bubbles in the line due to vibration, etc.. I put a filter just before the carb and just fill from there (disconnect fuel line on the tank side of the filter). If you're running a cowled in motor that you can't get to easily, run a t-fitting on the fuel line (between filter and tank), and run a fuel dot to the side of the plane.

Tim