I am not one of those ladies who hauls around a purse the size of a hefty garbage bag. I prefer to travel light, and my purse is just big enough for the essentials. My essentials are wallet and keys, cellphone and hairbrush, a paperback book and a notepad. I don't wear makeup and I've passed the stage of needing to stash a few diapers in there, so my purse is medium-sized.
In Oaxaca, however, I find that my list of essentials has expanded. Here is a quick run-down of the items that I have found, through trial and error, make a well-stocked Mexican purse:
1) Sunscreen. Although the weather has been pleasant here, it does get hot for at least a few hours a day, and I notice that when the sun is out, I burn much quicker than I do at home. I think the reason is that I come from far northern climes - even at the same temperature (say, 80 degrees) the sun's rays are hitting me at a much more oblique angle at the 49th parallel then they do here at the 17th.
2) Bugspray. Just do not go anywhere without bugspray, including to bed at night or out to a fancy restaurant. Must have bugspray. Reapply bugspray at least four times a day.
3) Cortisone cream. For the bugbites you will get anyway.
4) Bandaids. For the bleeding holes in your skin where you scratched the bugbites because you forgot your cortisone cream.
5) Toilet paper. Things may be changing in the wealthier, more touristy parts of Mexico (or maybe not) but here in Oaxaca, no bathrooms provide toilet paper. Not for free at least - Oaxaca is the only place I have seen a coin-operated toilet paper dispenser. Bring your own, you'll be glad you did.
6) Hand sanitizer. Many bathrooms also lack soap and even running water. If there's no running water, and hence no flush, there will usually be a big barrel of water and a small bucket, for manually flushing the toilet. But obviously you don't want to wash your hands in that.
7) Lots of small change. So you can buy toilet paper, of course, but also so you can hand out limosna.
Alms. The price you pay for being in lovely, historical downtown Oaxaca (patrimonio de la humanidad) is dozens of people either selling small items like postcards or gum; or busking; or outright begging. And believe you me, street people in Oaxaca are not like street people you see in your home town. You almost never see an inebriate. You never see an able bodied teenager with a clever sign. You do see ancient, wrinkled old ladies in native dress, mothers with babies at the breast and small children hiding behind their skirts, and plenty of sick people holding out the prescriptions they can't afford to get filled. Almost everyone offers something in exchange for your 5 pesos - a song, a flower, a blessing.
It's always 5 pesos well spent. Bring plenty.