Start small, finish strong. A great 3 piece plug set, Wendy Williams Anal Trainer Kit was specifically designed to allow you to work your way up the spectrum of backdoor pleasure.
Each plug is uniquely shaped to deliver distinct sensations; the smallest is smooth and straight, the perfect starting point, the medium is a perfect midpoint, mimicking the large on a smaller scale and packing a single bump, and the large is more substantial with 2 exciting bumps texturing the lengthy neck.
All three are flexible for the best possible positioning, but firm enough to penetrate easily. A very distinct base on each allows you to play safely.