I've been practicing this too. It takes some balance though

For example,

1: being your own advocate: if You are describing a problem, commit to it. Don't back down and don't say "ok" if someone tries to argue it's not important enough because "you and you alone found a problem". You're someone. You count. It's a problem for you. The solution isn't to not inconvenience others with the problem.

2: knowing when to be conductive to the solution: ok, so you've found someone who will help you fix the problem. But it's complicated. Complication can bring emotion out in people. It's not simple. So patience and support from both sides is needed. If you're describing a technical problem and working with someone to finding a solution, this does not require 'brute' psychology and putting feet down and just one person getting what they want. If anything, 'being cocksure' is the worst stance anyone can take in a solution finding environment.

3: if you are taking time off, tell them what days you are taking off. Don't ask. You don't owe explanations for being human. This involves you and you alone.

4: that said, respect context and boundaries in situations concerning other people and their jobs too. No one should be disrespectful. Everyone should be expected to say "sorry" and to be culpable when they did do something that inconvenienced someone else. We all should ask, respect, excuse ourselves and speak kindly. This isn't a case where Men should be 'more like such and such' or women should 'act like such and such.' Men, women, all people should stick to respectful standard. not a bully's standard.