I feel like a really important step is missing between steps 2 and 3: open an issue about the changes you'd like to make, and get feedback from the project maintainers. Unless you are just fixing an extremely obvious and simple bug, it is a really bad idea to just write up a pull request without getting an "I'd consider merging that" from a maintainer.
There are plenty of reasons that a pull request might get rejected. Perhaps a maintainer has already written some similar code and just hasn't merged it into a public branch. Maybe the approach you took isn't in line with the maintainer's vision. Maybe they just simply don't want to add the feature you want.
Randomly sending pull requests out of the blue is a good way to waste time and become frustrated. It's not very fun to write a bunch of code and have the maintainer just drop it on the floor.
There are plenty of reasons that a pull request might get rejected. Perhaps a maintainer has already written some similar code and just hasn't merged it into a public branch. Maybe the approach you took isn't in line with the maintainer's vision. Maybe they just simply don't want to add the feature you want.
Randomly sending pull requests out of the blue is a good way to waste time and become frustrated. It's not very fun to write a bunch of code and have the maintainer just drop it on the floor.