The only way to get better at block lettering is to practice drawing letters as well as the process of drawing the outlines around the letters turning them into blocky art style letters. Essentially, it's all about practice and experimentation. You can also practice using tools to assist you such as rulers and you could practice without tools to assist you. Trying variations of different block lettering can give you an instinctual ability to shape letters. You can also explore various forms of detailing in your block letters, such as shading block letters or adding lines. Most importantly, practice writing out a text and drawing the outlines around the text to get used to the basic block letter process. So, try all sorts of things and have fun experimenting with your block letter drawing.