With juniper berries and coriander seeds, angelica root makes up the big three ingredients in gin. The bitterness of fine earthy and woody notes dominates, continuing with a mild to strong astringency to finish with a sophisticated sharpness.
Usage 0.5g to 1g/litre. As an essential fixative start with 1/10th the amount of angelica to juniper.
Check out this link for some info on ratios and some recipe ideas.