I guess I'll post some of mine.
Tip #1 - Use Flint and Steel when taking out teams or someone with better stuff than you.
This helps me a lot. Each tick of fire takes half a heart each time. Usually takes a decent amount of health away.
Tip #2 - Have a chest route.
I never had a route till around my 400th game. I used to walk around aimlessly looking for chests. Now, I have a chest route with good chests on most MCSG maps. Note: Make sure to have some Tier 2 chests on this route (I would go on YouTube to find these routes)
Tip #3 - Practice.
I know this is a cheesy last tip, but practice makes perfect. I know that practicing helped me A LOT! I used to be one of those nooby players walking around with leather armor and an axe. I have practiced and practiced and I have gotten a whole lot better.
PM me if you have any questions about my tips.