Anal Play

Anal play rewards patience more than any other category, and almost everything that goes wrong comes down to rushing it.
Two things matter more than the rest: a flared base, without exception, and enough lubricant that you stop thinking about it. Silicone wants water-based lube, and that pairing is the one rule worth memorising.
Start smaller than you think you need. Size is the easiest thing to increase later and the hardest to recover from getting wrong.