Writing tips are great, and they often will help you become a better writer. But–
at some point, you will get overwhelmed. One post will tell you that every character–even that one waiter in that one scene who is only there to deliver milkshakes–must have a fully-fledged back story in order for your world to feel “rich”.
Another will give you a list of thirty ways to make your character seem interesting–whatever the hell that means–and it will demand that you give your character an interesting quirk in every scene.
Yet another will tell you that you can’t have problematic characters, but they should still have flaws, but not any flaws that actually make them un-likeable. Maybe have them smoke a cigarette, but god forbid they say something careless or rude to their love interest. (I could go on about that, but that’s a post for a different time.)
You can follow any advice you want–and a lot of it is actually very solid advice. But if you try to follow all of that advice at the same time, you’ll run into a big problem. You’ll either be so concerned with “getting it right” while you’re dumping out your first draft that it will effectively kill everything spontaneous and original about your work, OR, you’ll get to the editing portion and suddenly your manuscript will seem insurmountably un-fixable. I know because I have been in both of these positions.
THE POINT is that at the end of the day, your characters, your plot, and your manuscript are whatever you make them. If the writing feels flat, it probably is. At which point, you should ask yourself: why does this feel disingenuous, and go from there.
But if you like your characters, and if you like your plot, my biggest suggestion is to NOT go around looking for how to “fix” them or make them better. Everyone has opinions on how to do the best character development. Everyone has opinions on which cliches should be eternally banned from literature. Everyone has methods that might work stupendously for them, but will never seem to work quite right for you.
Just write, and while you write, pay attention. Where do your characters feel most themselves in your manuscript? Where does your plot surprise even you, the writer? Looking into what makes your own writing work will help you far more than anybody else’s “how-to” posts.
And cut yourself some slack.