As a first step, try and pay attention to things that annoy or frustrate you about other technical writing, and don't do those things.
I also try to assume my audience is a moron. Not because they are, but because any time you're doing technical writing, you presumably know more than them. Force yourself to not assume things are obvious just because you're familiar with them. IMO it's better for technical writing to be a tiny bit patronizing than to be lacking in vital detail. One specific example here is to either define any acronym before using it, include a glossary, or both.
I also try to assume my audience is a moron. Not because they are, but because any time you're doing technical writing, you presumably know more than them. Force yourself to not assume things are obvious just because you're familiar with them. IMO it's better for technical writing to be a tiny bit patronizing than to be lacking in vital detail. One specific example here is to either define any acronym before using it, include a glossary, or both.