Code things in the absolutely simplest way you can think of and be ready to throw it away at any time when you think you understand the problem enough and have

Code things in the absolutely simplest way you can think of and be ready to throw it away at any time when you think you understand the problem enough and have a good solution. Don't spend hours trying to design the perfect system, spend those hours coding it stupidly with the thought that you're going to throw it away later. Sometimes you do throw it away (but now you've gained a lot more experience with this particular problem, so coding it again will be a lot faster and with higher quality), sometimes you don't. Either way, to code fast you just have to code a lot and throw stuff away a lot. Don't listen to people telling you to stop and design the program properly in an organized way before writing a single line of code, it almost never works properly.