Really the best thing you can do is experiment. A lot. With various synths. Ideally stick with one style of synthesis across several synths for awhile until you feel you have a good working grasp of it, and can reproduce sounds that you hear in your head fairly well. Then move on to another type of synthesis.
Using multiple synths, I feel, is pretty important. Altho they each may use the same synthesis method (say, subtractive) they each have their own methods and characteristics to get what you're looking for out of them. By working with multiple various synths, you gain a deeper understanding of the sythesis method you're studying.
Also, the youtuber is FULL of good videos about various synthesis methods.
Have fun!
