Get a harness that adjusts easily, and wear it tight, much tighter than you would wear your clothes. Quality harnesses have waist straps that adjust with D-rings or with buckles. D-Rings are the double rings that allow you to thread the strap through both rings, then double it back over the top to secure the strap. Buckles are good because they are easily tightened again with a quick tug. they're less expensive too, and as they allow for micro-adjustments, they can fit more precisely than buckled versions. Generally buckles are best, however because once buckles are fastened, they stay firmly in place.
Unless you're a vegan, the best material for a harness is leather. Leather is smooth and soft: it warms with skin contact and seems to meld with the body of the wearer
- Extract taken from Sextoys 101 by Rachel Venning & Claire Cavanah, Founders of Toys in Babeland.