Rhodia Nr. 13 Notepad -- a handy small size
The Nr. 13 Rhodia pad is a handy size for shopping lists, personal memos, and sketches of quick ideas. It is not quite as pocket friendly as the Nr. 12 size (though it still fits in larger shirt/pants pockets), but the Nr. 13 sheets are larger and useful for more detailed notes and memos compared to the Nr. 12.
Of course the Rhodia-Clairefontaine paper has a nice, fountain pen friendly surface, plus it's rugged and economical enough for every day use.