If you want to make a good level the first step you need to take should always be to master the technical knowledge of the program youre using. Someone above me mentioned hotkeys and I would definately reccomend using them since they save a lot of time and boring work. Experiment with the program, build a few lvls and compare them, and learn from your mistakes. When you feel comfortable using the level editor and its features, you got the technical side down.

Next, try playing some high quality levels other people made. Read some reviews, and analyze what makes those levels good and why people like them. Try to follow some of the trends until you feel comfortable with your own style. Get input on your levels from other people and listen to what they say.

Finally, the most important (to me) part is inspiration. When I find inspiration, I let my work flow through me and try to feel what i make. If I don't make a connection with my work, I scrap it and start over because it will come out bland and uninspired. After you learn the technical skills, this part can be a lot of fun cause there's so many ways you can bring your ideas to life. BUT, like I said earlier, its really hard to do this until you have mastered the technical skills which is what it looks like youre having trouble with.

I had to rush this post, but I tried to offer my best advice to you so maybe one day you'll learn how to make a level that gets featured on the front page. Good luck :)