This is easy to remember for attack rolls, but there are things that you don't use all the time, like the precise descriptions of spells or special abilities. Of course, those are in the rulebooks, but it's not very conducive to a smooth RPG session if you have to stop and look up a rule or spell in the rulebook.
So I have taken to Homebrewery. It has style sheets that match the D&D Player's Handbook, so it looks like a page out of the rulebook. I create a document for my character and enter/copy all the rules and spells for that character. Most (all?) spells and class abilities are in the D&D5 SRD, so you can just copy/paste from one webpage into the other, add a bit of markdown and you're done!
I print these out, along with the character sheet, so that I have every information needed to play my character at the table. I've been doing this for some time now, and I really like how it works out. Just a tiny bit of work up front, huge time savings at the table!