I do themes maybe one or 2 per month not everyweek. I find that it puts to much pressure on me or the kids especialy the little ones under 2 if I do one per week. For example we are doing FISH the entire month of July. Now is the third week and one of my 18 month old just started to finaly immitate the fish and recognize the word. So one theme a week would not have been enough. I plan the activites at the begining of the month and always keep some to do on stand by. I do have speciale events like next week we have a fishing tournament, last week we built our own ocean and I always try to have one movie related to the theme (then have an activity related to it ). I go at the library if I don't have enough books on*the subject and the ABC's and 123's match the words we use related to the themes. I have a bilingual daycare so ofcourse I do both language at the same time. It's actually very easy to plan one or two per month at a time and there is more than enough ideas on the internet.