I have experimented making making limoncello using two different techniques,
Infusion via suspending the lemons above alcohol and have the vapors condensate and macerating the lemon peel and absorb the essential oils. I followed this recipe.
Soak lemon peel directly in alcohol. I followed this recipe.
I recommended you try whatever sparks your interest, My only trouble with technique 1 is that you need a warm enough place in your house to get a good evaporation cycle going. This can be especially difficult in the colder months causing a long turn over time.