Bottles I emptied myself:
Rinse thoroughly after drinking.
If they're labeled commercial bottles, see second method.
On bottling day, spray inside with starsan. Spray top with starsan too.
Relax while the beer carbonates.
Bottles donated by sympathisers
Rinse thoroughly and wince at the thick mats of mould growing in most of them.
Soak in tub with Oxi.
Peel off labels. Curse 8Wired's, Thornbridge's and a handful of other's woefully sadistic choice of label glue. Pray thanks to Brewdog and their easy-peel stickers.
Set aside till bottling day.
Spray inside with starsan and continue rest of first procedure.
It's still the single most off-putting step in the brewing process.
+1. I use a vinator or something similar to spray starsan into the bottles and then place the bottles on a bottle tree right before bottling.