I think it really depends on how much weight and how many earrings you want to wear through them. I love my 4g holes right now - I wear tunnels constantly so that I can wear anything I like through them, whether that be a couple of sets of 'regular' hoops, or my big old tribal sets. Many people are comefortable at the 2g size because it provides a few more options as to what you can wear through them when it comes to the larger sizes of earrings, plus you can start to find pretty tunnles with designs and such (my current obsession).

One thing to remember - when you wear the metal tunnels, you may not be able to wear your big tribal earrings until you get to the larger gauges. If you wear let's say a 12g earring through regular 12g holes with no tunnels that's fine because your flesh is flexible, but as soon as you put tunnels in, the curve of the earring now has to contend with an un-bendable straight tunnel. So for example, none of my tribal earring posts are larger than 10g, but i had to get down to a 4g tunnel before they would fit through because of their shape. Straight posts are not a problem obviously, but if you're like me and covet the Miao, Turkmeni, or Afghani hoops and rounded earrings, you will need either a larger tunnel than you'd expect or you'll need a flexible silicone tunnel or something like that.

Thanks very much for the advice!

Should I be looking for a certain shape when it comes to tunnels? For example I've seen flared tunnels (which I assume would work best) and simple straight tunnels. I'm also wondering if there are certain lengths of tunnels that I should look for.