During 1v1s it's sometimes hard to remember every detail about a build. With practice you can stop getting supply blocked but doing a build optimally takes some analysis as well as repetition.
To shorten the time needed to repeat the build, go to single player and start doing the build against the computer. Save the game once you're past the part that you already know well enough, for example in a rax-FE build you'd save maybe after starting the CC.
Copy a build from a VOD. Try to write down every single relevant detail. Then, when you're practicing it, if you mess something up, see how much it affects the build, and re-load the saved game and do it again, until you can do it perfectly. For example, in Flash's TvP double expand build, I found out that if you delay the 2nd gas even a little bit, you will not have the 600 gas needed for throwing a bunch of factories about 5 minutes later.
Here are a few examples of me practicing build orders:
Flash TvP double expand
Bisu PvT expand with 3 gates
Flash TvZ 5-rax expand