Pick any random ingredient you enjoy and cook it using a few different techniques and a few different time/temperature combinations. Try to understand what is happening with that ingredient, why they taste different and which you prefer. You'll soon get a feel for how different combinations of time and temperature affect different ingredients and will often be able to guess how new ingredients will behave based on your experience with similar ingredients.

I personally consider Alton Browns old TV show Good Eats as a great introduction to cooking following this approach. Most episodes are dedicated to one ingredient or one technique and really breaks down the science behind everything and how different factors affect the outcome. Once you understand the basic techniques and ingredients, putting together recipes becomes a lot easier.