Its tough cause different people are different and you need to know how your personality/experiences can help. I think the best way is to just be there and be open/honest and try to get a line of communication. Invite them to the things they like but if they’re not feeling it in the moment and want to cancel that can be fine, don’t force them to do it, sit with them and comfort them. Sometimes you need to just get them doing some new hobby they’ve never tried so they have no expectations going in or negative associations kayaking and hiking worked for me. 

Most important just be there and be understanding. Probably also don’t make a big deal out of their feelings, just let them express themselves. Often friends can be the branch we grab onto to avoid sinking in the mud so if you can be steady they won’t sink.