Best way to get a crispy bottom crust on homemade bread

The biggest thing is moisture and heat working together. You want steam in your oven during the first part of baking - that keeps the crust from setting too fast and lets it expand properly. Then in the last stretch, you need direct, intense heat under the bread to crisp that bottom up. A lot of people use a preheated baking stone or steel because it holds heat way better than a regular sheet pan and gives you that contact heat you're after.

Getting the stone or steel really hot matters more than most folks realize. Preheat it for at least 30-45 minutes at your oven's highest temp. When you slide the bread on, you want to hear a serious sizzle. For the steam part, you can throw a pan of hot water on the rack below, spray the oven walls right when the bread goes in, or if you're feeling fancy, throw some ice cubes directly on the hot stone (careful with that one). Keep that steam going for maybe the first 15-20 minutes depending on your oven, then let it escape so the crust can actually crisp and brown.

One more thing - don't pull the bread out too early thinking it's done. The bottom needs genuine color and should sound hollow when you tap it. If you're still getting a pale or soft bottom after all this, your oven might have a cool spot or your stone isn't getting hot enough. Some ovens are just weird about heat distribution, so you might need to rotate the bread halfway through or move your stone to a different rack.