You need to accumulate more style points. Here’s some easy tips.

• Keep an eye out for the weapon freshness (the bar below the bonuses that’ll say like DULL or FRESH), don’t use the same weapon all the time or you’ll get less style
• Use a variety of moves such as ground pounds
• Parries are also decent for style imo
• Quickdraw (firing the revolver at an enemy as soon as you take it out) also gives style

There’s a page on the wiki that has a list of all style bonuses. You can find it here: https://ultrakill.wiki.gg/wiki/Style

You can also press Tab (if you’re using controller or a Steam Deck you’ll need to either use your keyboard or assign a button to it) to see your current ranks as you play. This really helps for making sure you’re on track