I asked my students to make their very own calendar, showing them my own calendar, pinned up on the wall of my classroom. I had the students draw the boxes and write at the top of each column the day of the week. I then went through the months of the year and gave them twelve sheets of paper to write each month of the year. [You may also wish to look at seasons and write down the season for each month]. Once the months of the year were written at the top of each sheet of paper, we wrote in the numbers 1-31 (depending on the month) in each of the boxes in the top left hand corner. When they had completed this, they then have a calendar. You can, if you wish, set them a monthly task to draw a picture representing something you've been learning that month, or you can just have a flip book of the months.
Once the calendar book is complete, you then tell the students they must record one new word they have learnt each day on the calendar. What I like about this activity, is that they have to choose one meaningful word each day, rather than keeping long lists of words, which they will easily forget by the next day. The theory behind this is, if they learn at least one word well, they will begin to use it and understand it.
I would stress that this activity does require you to refer to it throughout the year, to keep students on top of it. Many may forget about it, so perhaps give them a page a month (which you could pre-print, if you didn't want to go through the days of the week/months of the year), but some will use it every day, and may step up to writing down two or three words. The goal is that the words are meaningful and the students remember them in six months time.