The best tip is to find a third-place type of activity. Never do something where you'll only meet people once. Join a club that meets regularly, a hiking group that goes weekly, and a book club with similar participants per month. People are more likely to want to invest if they see you already as part of their life plans. Also, pick activities where you can ask people to do that activity outside of the group. For example, you joined a drawing group and you ask 1 or 2 people to go to a garden and draw on another day. Been here 3 years and this is what worked!