I have participated in miniature swaps since the mid 1990s. There were a few years where I sat out some swaps due to real life getting in the way. I have 35 plus or minus room boxes and several more in the works. I love miniatures. If I didn't swap, I don't believe I could do miniatures.
It is required that your learn to make things and make them in some quantity (generally 10-15) and with some quality. Most of the swaps I do are central point swap so they are all mailed to one person and at the close of the swap, you get back separate swaps from the other participants. I like room boxes filled to the gills, and this you can see if you look at the slide show in the right column.
I certainly couldn't afford to do that if I didn't participate in swaps. Recently I had the opportunity to participate in a swap entitled as "shops". Each participant listed the type of shop they wanted items for. I listed a choice of two and they were antique shop or clock shop. The attached photos are of the items I got for a clock shop. Along with the clocks that I already have, I do believe I will have my completed clock shop ready to share just any time. 3rd photo down has a dime so you can see the size of the items.
You can see that many are handmade and others are purchased. Also an option. Generally the requirement is that the retail value of a swap should be $5.
Over the years, I've had the most positive experiences with swaps and have met some very talented people.
How do you find a swap group? Get on the internet and look for them. You generally have to apply for membership and each swap group is different. Some just share information and others do lots of miniature swaps. I will not list the groups I belong to due to the privacy of the members. I've gone in and out of several groups depending on how they are run and the types of swaps they have. It's worth the effort to find a group that you are compatible with.