Welcome!
I'm living in the French-speaking part so my experience could be a little bit different and I welcome others to comment but here are few considerations.
If one is just moving to Switzerland it could be quite hard to find a normal long-term apartment right away, because one does not have the set of standard documents, most essentially 3 latest payslips, an already issued permit, a contract post probation period.
Commonly, people do the following,
- rent an expensive apartment for 4 months, on the 3rd month one'd probably have the set of documents mentioned above, and can start looking for an apartment; by expensive I mean airnb and alike offered by smaller firms, one needs to be sure that the owner is fine with letting a tenant to officially register (ie. a contract is required or at least a written note etc.) - ask about it in advance
- some companies are able to hire agencies, that'd bypass the necessity of having to get the set of docs first, but their range of properties can be more limited quality and price wise, also maybe you can find such an agency yourself but is it worth it, I don't know
- some people probably manage to find a good enough guarantor to convince a rental agency in a pro-tenant market
- some towns probably have a pro-tenant market and more flexible, but I don't have experience in this regard
Now, as for the stage of visiting appartments, indeed,
- be as a fast as possible when you like an apartment, have all docs scanned on your laptop and go to a nearest convenient place to send them right away (it's sometimes in physical form too, so you may want to have a set of print outs ready as well)
- as for penalties, some agencies do make you sign that you'd pay a penalty refusing an approval, there're some threads about it and people conclude this is barely legal but I'd personally prefer to completely avoid such situations and only sign such forms if I indeed like the apartment for sure, so just pay attention to that
- try looking on Facebook Marketplace, I've found it more efficient when I could message directly a leaving tenant