- Get the basics/staples.
- Don't get any fad/trend items—i.e. ripped jeans are in (again) right now, but don't bother, just get a good pair.
- Fit means everything.
- Go for the 'uniforms' in the style you like (prep, street, or whatever).
- Quality over quantity (this is often related to fit).
- Dress to your body (not too tight or too loose).
- Honestly, just go to https://www.reddit.com/r/malefashionadvice/ and go through the sidebar.
- You can be incremental. Jeans are fine, just get ones that fit well, and get a pair in black. Swap the hoodie for bomber jacket or denim jacket. Get rid of your graphic t's and t's with slogans and 'funny' things.
- It doesn't have to be expensive at all. You can go to H&M or J.Crew for your basics (white/black/grey t's), maybe a button-down (oxford) or two, and a pair of navy chinos. Don't ever get jeans from brands that do lots of things (like H&M, Zara, etc.). Even if you do this, jeans don't have to be super expensive—Levi's have good fits, then there's other ones like Nudie's, Cheap Mondays, etc.
- Have some fun and experiment a little, but often you need to know the basics first to do this well (same for everything whether it be fashion, programming, art, or writing).
- You can completely skip getting someone who dresses well to help you out if you just aim to build a solid, basic wardrobe, and can shop by yourself.
- Always wear a belt. Get a simple tan leather one—you can wear it with navy chinos and shorts, black and dark blue jeans, etc. Get a simple watch. Go digital with a cheap Casio or analog.
- Don't overthink it. Just go for solid basics.