A good shop will have staff who know their stuff. Ask them these:

• "Which filters fit this dripper?"—Make sure you grab the right ones.
• "What's the grind size for this method?"—They might even grind a sample for you.
• "What's the ratio you recommend?"—Get a starting point from someone who's tried it.
• "Do you have a pour-over demo?"—Some shops will show you the technique. That's gold.

Don't be shy. These questions save you from trial-and-error at home.