One of the greatest tools to ensure you have consistently good food coming out of your kitchen is to get a cooking thermometer. This is in no ways “cheating.” Professional kitchens deal with precise temperatures all the time. Gone are the days of forgetting to pull out the roast 20 minutes ago or second guessing whether or not your chicken is safe to eat.
There are a number of thermometer options out there from instant reads to lasers. My suggestion for starters is to get a good probe oven thermometer. With it you can get decent readings and can roast meat in the oven by setting it and forgetting it (until the thermometer alarm goes off at your target temperature).