Install a FPS Performance | Butterium server through the Control Panel (Servers → Select your server → Game servers → Add Game Server → FPS Performance | Butterium)
I find this to be very helpful with everything and learning how to run my own server, I think it can be a bit difficult to find a way to put mods but for the most part it works! The server itself is great, not much lag and is everything you would expect in a minecaft server!