I grow all my lillies in pots outside so I can move them into a prominent position when in bloom and tuck them away when they're just foliage. I have 9 bulbs in one 60cm pot and just 5 in another so I fill thegaps with annuals like lobelia. I used to have many more but got rid after a bad infestation of lily beetle but I have succumbed again.
I put a layer of wine corks and grit in the bottom for drainage and then use good quality general purpose compost. I give occasional liquid feeds of rose or tomato food to help the bulbs produc ebetter flowers each year and also add a handful of pelleted chicken manure to the soil each spring for a general feed.
You need to keep a regular eye out for red lily beetle as they and their young will devastate lillies in no time. Squish the adults and remove the slimy globs of larvae with a blast from the hose or a damp cloth.