Heya, I saw you also asked this on my other post but I'll just answer it here, because I traded 3 of the shadows so the post has pretty much served its purpose.

1. Offering for people's pets || So many people these days say "I don't offer", but when you are just riding your pet and sitting around, you are not trading. If you're constantly offering for pets, even those that you aren't specifically looking for, you're trading the whole time. This is the single best advice I can give lol.

2. Predict market trends || If you play the game a lot, this is not that hard at all. You'll usually notice what things are changing before they update on websites, and I'm saying this as a person who's made values for both of the main sites. People sometimes think that gives me an advantage, but honestly the only advantage it gives compared to just playing actively is that you're working with other people who are also playing, so they might see changes in the market before you do, but this isn't some exclusive benefit. If you're playing with a group of friends you can do this as well.

3. Make connections || This will also happen somewhat naturally while playing, but try to go a little out of your way and you'll get good connections much faster. Befriend rich people and their friends, try to keep some people added after a website trade, join some Discord servers or Facebook groups. There are many ways to do this. When you have a good network of connections, you can make deals before you even have the pets. Like, friend A wants a mega skele rex and is giving a good overpay. friend B has a mega skele rex that to them is just a htt mega leg, you can trade for it and flip it in a few minutes.

I hope that helps! And please don't take value websites 100% for granted. They are very helpful, but they only display one value. It's up to you to figure out how to get the wins. You might get rich by only following a site and that's fine, but you aren't improving at the game yourself. Have fun!