Despite what many people think, programmers spend far more time reading code than writing code. Figure out ways of reading code that work for you, using tools

Despite what many people think, programmers spend far more time reading code than writing code. Figure out ways of reading code that work for you, using tools as needed. For example syntax colouring was a great reading productivity improvement. If you write your code in a consistent way then it will also be easier to read, although that doesn't help much reading other people's code. (This is why source formatting is a big deal to some.) Ultimately you will develop a sense of "code smell". A quick glance at some code will give you an impression of it likely being right or having problems. (For example lots of variables and control flow is more likely to have bugs. Seeing lots of zeroes and ones points to off by one issues.)