I usually do one of the first three that you listed. If I have some experience with the situation, I will add that to my responses and how I handled things. I typically can see from both points of view as well, so I may add that if I feel the person needs to see that other side, too. If I cannot add experience or write from someone else's view, then I'll support them... unless I think they're too ridiculous.
Tough love. I'll be honest with them, try to show them both sides to help prove my point. I usually stay as diplomatic as I can. I only play the part of the devil's advocate if it's someone who's trolling. I have zero patience for that.
I share my opinion with them, most of them see my perspective in how I view it. I help some see both sides, some can't accept it, but at the same time cannot deny the fact. I try to support them, especially when they're in the hardest times, or something heartbreaking has been going on in their life. I give them the brutal truth if they don't understand or cannot handle their own situations.
I just try and be nice to them. I reassure people about their bodies (so many dick size questions about perfectly normal dicks smh), and tell some people basic sex ed that I'm rather appalled they weren't taught in school (the education system needs to step it up tbh). I answer quite a lot of questions as well where the person isn't really looking for advice so much as just venting. I just try and make them feel heard and cared about.