Because a dresser is, essentially, a stack of drawers that you can use for out-of-sight storage, one of the main considerations you'll have to make is the number of drawers you need. However, with a small dresser, you have expected size constraints.
The most important thing is to start by measuring the space that you have available. Remember that a standard dresser is about waist tall (which means about 26-44"), 16-20" deep, and anywhere from two to five feet wide. That's a lot of variances! A smaller dresser is likely less deep and less wide, but can potentially be very tall to take advantage of vertical height. This means that you could choose a low, narrow small dresser with only two or three drawers, or have as many as seven or eight and be more like a tower of boxy drawers.
How many drawers should you choose?
Start with your measurements to see what's available. Narrow down your search criteria so you're not seeing anything that's too wide for your space.
Then, consider your storage needs. Do you only have a few knickknacks you need to stow away? Are you purchasing this small dresser for a small amount of clothing (for example, to place in a young child's bedroom)? If so, you likely only need two to three drawers. However, if you're looking to get as much storage space as possible, for example, if you live in a smaller space, pro tip! Go as tall as you possibly can. There are small, narrow dressers that have as many as five or six drawers; choose one of these for your space to store as much as you can!