Here is a recipe for "Basic Herb Butter" along with different variations by Southern Herb Growing by Madalene Hill & Gwen Barclay.

Basic Herb Butter

½ pound butter either salted or unsalted, softened
1 tablespoon fresh chives
1 tablespoon fresh parsley, preferably Italian a/k/a flat leaf
1 tablespoon other fresh herb or combination of 2 or 3 (some good ones are dill, tarragon, minced garlic, minced lemon grass, to name just a few)

Chop herbs very fine and work into softened butter. Add more herbs if needed, but remember that the flavor will become stronger with a couple of hours of storing in the refrigerator. Be sure not to include stems.

Variations:

1-2 Tablespoons lemon juice
1ld and/or pepper
1-2 cloves minced garlic
1 tablespoon Dijon mustard
1/8 teaspoon dry mustard
1 teaspoon curry powder
1 teaspoon celery seed, ground coriander seed, caraway or fennel seed
1 large fresh by leaf, very, very finely chopped
1/8 teaspoon Tabasco or other hot pepper sauce or 1 teaspoon grated hot pepper
½ teaspoon paprika

All the measurements are approximate and can vary to individual taste.

For the crab meat, the basic recipe with the garlic and dill and/or lemon or lemon grass added would be very good. Or you can do just the softened butter with only the garlic, dill and lemon grass.

Your herb-combination list is endless. Just put in what you like.