Here are a few links to advice on drought-resistant plants and gardening techniques. Please let me know if you have anything to add, links, hints etc – in English, French or German!
Cut bottom off one of those inevitable large plastic bottles, partly bury it top down behind thirsty plant and fill with water, which goes to roots, not surface.
I have put cloches over young vegetables to keep moisture in. You would think they would fry, but no, it helps.