I have experienced couch surfing a couple dozen times both as a host and a guest, every time it was a positive experience. While I am not an expert, there are things to keep in mind if you are considering it:
1. Find someone who has similar interests as you and is looking for an experience with as much or as little interaction as you would like. If you are arriving mid-week and are hoping for a sightseeing host, if your host’s profile doesn’t specifically state they are available for such things, they probably aren’t. But on the opposite end of the spectrum, some hosts are looking to share stories, photos, some drinks, maybe cook dinner and share favorite recipes. Take the time to find a host that is a good fit.
2. As a solo female traveler, I only couch surfed hosts that were female or couples / families.
3. Find people with at least a dozen reviews and read every review. Never stay with someone who has bad reviews from past guests or hosts.
4. Make sure your host has been security verified by the Couch Surfing website, as a basic security measure.
5. It is customary and good manners to bring your host a gift at some point during your stay. For example a bottle of wine, contribute to a meal being cooked, take them out to dinner, just something to show your thanks. One time I took a family on a local sightseeing boat; they had lived there for years and never went on the boat ride until then; they were incredibly thankful. Other people who have hosted me ended up contacting me later when they were traveling to the US and of course I agreed to host them.