Here in Slovenia, the use of wild garlic is quite widespread. Although the whole plant, including bulbs, is edible, leaves are most commonly used.
I tried only leaves so far, so I can share my experience with only them.
Young, light-green leaves are a bit more aromatic, but smaller; older are darker and larger. I pick a mix of both and look for undamaged, clean leaves. (I found very few with a bit chewed out by some animal; sometimes there are some webs on the bottom side, maybe spiders, not sure. It's no problem removing them, but if a leave is already "settled" I like to leave it intact.) I pick a leaf with the stem, somewhere at the middle.
Leaves of lily-of-the-valley are similar to wild garlic and are poisonous. To confirm that a leaf is wild garlic, I do the following:
- smell the leaf (must be like garlic),
- look at the underside of the leaf (a bit lighter than the top),
- each leaf grows from the ground on its own stem, whereas lily-of-the-valley grows several leaves from one stem (seen here),
- lily-of-the-valley has pronounced lines on the underside (also seen in the linked image above).
A good handful should be enough for one person for a risotto. I put it in a paper bag and it stores well several days in the fridge, but it's best used fresh to keep the most aroma.
Wild garlic can be used raw in salads or more commonly to add flavor to soups, risottos, etc. It can be made into a pesto for later use.
Rinse leaves before use. Chop them to your liking and add them towards the end of your dish so it retains more flavor. You can also sauté it on olive oil or butter beforehand for a minute.
Edit: Added two recipes
Wild garlic risotto
Boil risotto rice (half to one cup per person) with just enough water that it's mostly gone when the rice is done (commonly around 1 unit rice, 2 units water). Melt butter in a pan and sauté chopped wild garlic (30-40g) and 2-3 cloves garlic for a minute, add cooking cream, season to taste (nutmeg makes a good seasoning here). Pour this into the risotto a few minutes before it's done, mix well, cook until the rice is done.
Wild garlic pesto
Chop 250g wild garlic, 10 garlic cloves, 200g sunflower seeds (or pine nuts), mix with olive oil, season with salt and pepper. You can blend it all in a blender for a finer paste. Fill into a jar and top with olive oil.
To continue adventuring with recipes, try google-translating for "čemaž recepti" (Slovene for wild garlic recipes).