Default [Q] Out of practice flasher!

Hi all,

First of all, apologies If i have not looked hard enough!

I am currently on CM 11.0 which I installed using the neat new CM installer app. I have enjoyed it for a bit, but find it is really draining my battery. Have tried the usual fixes, but this is definitely more of a drain than when I was on stock.

I am looking to install a new ROM that is slightly more modified with battery and performance in mind. The problem is, I haven't flashed custom ROMs the old fashioned way since I had my Desire HD and I am now a little nervous as I have no idea of the procedure involved. I am obvisouly already rooted as I have CM 11.0 installed, but what's next? Is there a good guide somewhere for noobs that I am missing?

Many many thanks for any help!