What are the 10 things you shouldn't do in Switzerland?

1. Being uncivil is unacceptable. The Swiss are particularly civic-minded and take rules very seriously; they won't hesitate to approach you and remind you if you break them, in their opinion. Oh, and address everyone formally, if the language allows, or generally with a degree of courtesy.
2. If you spend a long time there, they'll expect you to learn the language. They're mildly xenophobic and have reservations about people from Southern Europe and this reservations intensifies the more they perceive you as not trying to integrate.
3. Ask for bottled water. They'll charge you an arm and a leg for it, and in Switzerland, the tap water is delicious. If you ask in the local language, they won't play dumb (I speak from experience). "Un verre d'eau, s'il vous plaâit."
4. If you don't like cold water, don't swim in their waters, or be prepared :P. They tell you that 18°C ​​water in summer is warm. They're crazy, seriously.
5. If you're not on a budget, avoid eating out too much. If you're sightseeing, I highly recommend finding somewhere where you can at least make yourself a sandwich (I recommend cheese, it's delicious and very reasonably priced). But in general, eating out in Switzerland is expensive.
6. Expect to pay for everything by card. Outside of large establishments, you'll need to have local currency.
7. This brings me to another point. Avoid paying in euros, even if they accept them. The exchange rate will be extremely unfair.
8. Avoid staying too long in one city. I think the charm of Switzerland lies in taking a car or train (which, by the way, work very well despite the price) and getting a little lost; the nature bathed by the Alps is breathtaking. The cities are especially cool when there are celebrations. In Geneva, I have very fond memories of the "Fête de la Musique" or the "Fête de Genève".
9. Unlike other European cities, the fact that things like prostitution and marijuana are legal hasn't made it a tourist attraction. So, well, don't treat it as one.
10. Pay attention to the opening hours. If you're Spanish, you already know that meal times vary. And in general, shop hours are quite reasonable; shops in Geneva, at least, close at 6:00 PM except on Thursdays. Then on Saturday afternoons they close again until Monday.