What % you sell depends on your risk tolerance and initial investment. For example perhaps you sell 50% after the price doubles, then you'll have your money back and hold half of your current moneroj.
I think a good way to go about it is to decide on the amount of XMR you want to own long term and then buy more, perhaps 2x what you want to own. Then you diversify as the price goes up until you have sold the exceeds, recovered your initial investment and still hold your preferred long term position.

That part is easy enough. Every time I try, the bar just raises with my buys though, and I never amass more than I want to hodl. Not sure where this ends. nioc's defective sell button seems to have infected my system. Perhaps I can free it up by
buying more. I should just buy on margin, then I have to sell eventually

TheKoziTwo, thank you very much for your posts. Always great perspective.
I don't have the means to take this advice of yours. I have built my Monero house brick by brick over the last 2 years partly by being more frugal than TC. I have had some rough financial times. Yet when somebody asks, "how are you?" I respond, "never better" because it's true. Happy Thanksgiving.
https://www.youtube.com/watch?v=rYeWnbmFUhQYou know, what I find very sad is to hear the stories of the guys who was around here back in 2010-2012 but never seized the opportunity that was there, right in front of them. One of the best opportunities in the history of mankind. Maybe it was their nagging wife that didn't want to skip a night out in town to put a couple of hundred bucks into a silly internet money project. Maybe they had a few friends who talked them out of it. Maybe they thought it was too much work to sign up on the exchange and transfer money to a weird foreign bank. Maybe they just wanted a cool car or a new couch. Whatever the reason, they let the opportunity pass them by, and when it comes to those who really believed in bitcoin, but still let other people convince them not to buy, I find that a bit heart crushing.
When you're really excited about something, you tell people, and they naysay the shit out of you. It can be hard to stay focused and motivated. There's a quote I like, by Garret Burgwardt.
I haven't been blessed. It was through my foresight that I saw bitcoin for how valuable it was. No man helped me along, and many discouraged me.It's not about how much you have, it's about using what you have. Think about it. Those people back in 2010-2011 could have put a $100 bucks in and held, but they didn't. They didn't
need much. They just had to not let go of their dream.
What you are doing. What AP is doing. I'm a big fan of such strategy.
Living a few years of your life like most people won't, so that you can live the rest of your life like most people can't. That's more than putting that $100 bucks in. That's real determination. Passion.
Back in 2012 after the bubble to $31. I was quite frankly piss poor back then. But after that bubble I had an epiphany: "Trying to trade myself more bitcoin is foolish. This could very well be the greatest bull-market in human history and here I'm trying to time the market for pennies?" After that day I was a changed man. I only bought bitcoin, never traded, and I kept buying all the way down.
I quadrupled my investment during that period. It wasn't a lot, and it was all I had. But man, am I glad I never gave up that dream.
Your story reminds me the story of Warz. Perhaps you are Warz?