saying it out loud then most likely the grammar is wrong.

How I and most of my friends determine if our grammar was right or wrong back when we were college students though I still apply it to date lol.

No matter how good you are at writing or how good you are with the English language, it's all moot if you don't know by heart what you are writing. As much as possible write only things that you have personally experienced or have great information about.

Probably the best advice in this list. Emotion and passion is clearly visible when one speaks from their own experience rather than trying too hard on a topic that doesn't suit your style.