Easy answer. Use some common sense/courtesy and remember the golden rule.
Some people go the extra mile to return discs, being willing to pay shipping, meet at extremely inconvenient times or locations, drop it off at the owner's residence, etc. That's fine if you want to do it. It's also completely understandable if you don't want to or don't have the time/energy/money. My conscience doesn't let me throw discs with others' name/number unless I've reached out to them. This means I usually text people or sometimes just leave discs that I find. It's strangely enjoyable to return a well-loved disc to an appreciative loser. But it's also rather frustrating to go out of your way to return a disc to someone who doesn't seem appreciative. I've experienced both many times.
If someone finds your disc, just don't be unreasonable. Give them a simple option such as meeting you at a course where you/they play frequently, or such as leaving it in a location where you can pick it up. Don't be the guy who expects someone to ship them their disc, meet at an unreasonably specific time, or whatever. If it's a disc you really appreciate or one with some value, it never hurts to give $5 or offer one of your other discs to reward the finder/returner.
I'd link to one of those threads discussing this topic, but the discussions turn into such ridiculous such arguments that I'd rather you just not look...