Simple routines govern our lives and the game of golf is no different.
Tee up your ball, check your alignment, waggle once or twice and go. These simple motions help you to perform the repeated action of your golf swing.
It is important to get into a similar routine when you're reading the green.
Start your read before you even reach the green. You can often get a good look as you're passing by on a previous hole, taking note of pin position and overall slope.
As you approach the green on the hole you're playing, start taking another look at the slope of the green. It is usually easier to get a perspective of this from a few yards away than actually standing on it.
Make sure you're taking a look from both sides of your ball. That will help you to get an accurate read on sidehill breaking putts while also giving you more information on speed for putts uphill or downhill.
Get in the habit of marking your ball. This not only allows you to use the ball's trademark to align your putts but gives you one last low-level look at the cup.
Always take note of other putts from similar lines to gather more info and be sure to do your "reading" while others are putting or hitting from off the green so you are ready to play.
Establish a routine and repeat those steps when you're on the putting surface. That familiarity will build confidence and increase your chances of success.