This question has been in my requests a lot of times. Since some servers are getting graded harshly on their servers I've left in-game. Here's some good ways to have a REALLY good review on your server.

1. You should have a great spawn, something I'll want to screenshot and advertise the server to my friends
2. Have friendly staff. You want to have me back so don't have a staff that'll ban me for no reason.
3. Have an ACTIVE server. I don't want to come in the server and be alone the whole time, so it's best to have a big server.
4. Have multiple types of gameplay. I might want to have optional PvP so most likely make a PvP portal. I also might want a parkour area. You should have parkour at your spawn. And non-PvP survival! Like a singeplayer world.
5. Don't have TOO good but an average starter kit (Stone Sword, Stone Pick, Wooden Spade, and Wooden Axe).
6. Lastly have claim stones or a spade to claim stuff with. I don't want my creations to be griefed so it's best to have that.

So those are some things that'll get you an overall grade of B or higher. So if you want me to review your server, don't make a waste of time. I'll make another post on what you'll get graded on in your server.