Best way to handle stubborn outdoor grime with a pressure washer?

Hey everyone,

I’ve been working on cleaning driveways, decks, and patios with my pressure washer but I’m not getting the best results.

Here’s what I’ve tried so far:

• Standard pressure-washing (2000–3000 PSI) with detergents
• Letting surfaces air-dry overnight
• Multiple passes with different nozzle angles

Still, some stains refuse to come off.

So I’d like to ask:

1. Do you adjust PSI or nozzle type depending on the surface or how old the stains are?
2. Any tips on prepping surfaces—like grit, cleaning solutions, or methods—that make pressure washing more effective without damaging the surface?

Thanks in advance for any advice!