I am in no way an expert on anything...like anything at all. But I have learned a few things in the last couple of years that I wish I had known when I started thinking I wanted to get an agent or publish a book. Most of the things I've learned seem like common sense, but surprisingly, in the excitement of getting recognition for something that is so personal, we often forget what we know is just good etiquette. Along with that, I've fallen into a few 'things' that I've been fortunate enough to have far smarter people than I help me navigate my way through. So here's a pieces of not-advice-but-something-like-it from someone who is still finding their way.
If you wouldn't say it to someone's face, why would you say it online? You would absolutely think that this is just an accepted truth. However, the internet gives us a certain anonymity (or so we THINK) and there are times when people type before they think. Don't do that.
The only way you get better is by listening to the advice of others. Not everyone, but someone. You have to choose a tribe of people that you trust. That you know want what's best for you, will be honest with you, and can handle you at your worst. If you have people like that, who will read your writing and be brutally honest, with the best of intentions, then trust them. At least enough to truly consider what they're saying.
No agent is better than the wrong agent. This one sucks but it's true. These people are entering a relationship with you. Would you go into a bad relationship, JUST to be in one? There was a time I would have said yes, but as you get older, you learn to care more about your own well-being, Writing is no different. You want someone to be your champion and I am completely convinced (most days) that the right agent is going to be worth the wait.
As in life, envy gets you nowhere. It's easy to be jealous when you hear an announcement from other writers or from agents you stalk- I mean follow. But the thing is, you don't know their story. You don't know how hard their fight to get to where they are was and most of all, if they got there, then they probably had some pretty phenomenal writing. It's too hard to get somewhere in this world if your writing doesn't rise above. So they deserve it and it doesn't make you deserve it less. And, their success doesn't lessen your chances or your talent.
Go with your own style. I've been trying my hand at plotting and it just doesn't work well for me. For the co-authored book I'm working on, yes. But for my own writing, I just can't do it. At least not yet. I like to get lost in my writing and having to plan it all out first, throws me off track. I can always go back and edit and make plot points along the way. As much as I hate the term, I'm a pantser at heart. That's not right or wrong. It's just what works for me.
There's more. There's always more. But that's it for now. Nothing we do is foolproof. There's no list or step by step manual to succeed. There are things you can do to make the ride smoother but basically, you have to do what you should be doing in your life: be who you are, to the best of your ability and hope that good things come to those who wait...politely.