Liquid Allowance,Hand Baggage.

Hi everyone,we are off on our jolly's in just under 3 weeks and i have a question regarding liquid allowance in your hand baggage.We are for the first time doing the twilight check-in as we are having a relaxing stay at the hilton the previous night,we plan to have a small carry on case but i am un-clear on the liquids,is it just one clear 20cm x 20cm bag per carry on bag or can each passenger put there own amount in the same case eg 3 20cm x 20cm clear bags in the same case,any info on this matter would be great.