I personally wouldn't add the drops into the shadow container--some eyeshadows develop a film/hard shell if they come into contact with something wet. I personally would take a clean brush, load on the e/s and put a drop or two or mixing medium and apply. Or it has been suggested previously to scrape or take some e/s out of the pan (you could do this by a brush or scrape with something clean) and put it on a plate or something and do your mixing and applying from there---which then wouldn't affect the integrity of your original e/s. Other ppl have also designated a portion of the e/s pot to just wet/dry but I think it could be tricky.
I favour the loading the brush then make that wet and apply, but then when I go to do the second eye I'll take a new clean brush so I again don't get the e/s wet (bacteria can also grow this way) HTH!