The hardest part of making beats that rock is just the getting started part! And yet it is the single most important part. Without getting started, not amount of awesomeness can evr turn into beats.
But when you push past that first note, a beat will start to form and lead you to where the music wants you to go. So just start. Stay focused because you are in charge, in charge of the sound.
You control the music and no one can tell you what to do.
Now because getting started making beats is the hardest part it is also where most people get hung up in the process. Whether it is fear, or uncertainty, the only thing you can do is to take action, to lay down a first beat. No matter how bad it is.
The next beat will be awesome. You just have to beat you fears and anxiety, so just do it!
Here is a good place to start… keep a recorder with you so that when a hot beat pops in your head, you can capture it before it slips away. This will give you inspiration when you sit down to pound out new beats.
After that, you can come up with a title… infact the title could lead the entire song. Once you have a working title it will help you know where the tempo, the lyrics and emotion should go.
The title is like a road map.
With the title and feel of the beat in place, the rest will just flow. Just go after the common structure of a song which is a verse then chorus then verse and repeat the chorus.