Customs, duties, MwST etc.
Are you having something sent from home? Or did you buy something on-line and you're having it shipped to Switzerland?
With Switzerland not being a member of the EU, all incoming goods, packages etc. are subject to customs processing. The rules are undoubtedly quite clear, but how and when they are applied and what the actual costs are is not quite so clear.
Mehrwertsteuer / MwST
The Swiss Mehrwertsteuer (VAT) is typically 8.0%, although some areas such as food, medicines and books are only subject to 2.5%. There is even a separate rate of 3.6% for a stay at a hotel including breakfast. See Umsatzsteuer_(Schweiz)
For goods bought outside Switzerland but shipped to Switzerland, there is generally no VAT applied by the sender. (sometimes firms unaccustomed to international customers will mistakenly apply VAT anyway ...). When the goods are imported into Switzerland, Swiss VAT is applicable.
Some goods are also subject to import-duties. This section to be completed.
In general anything and everything is subject to customs, VAT and duties. In practice there are variations.
There appears to be a minimum value below which no customs processing is done. I have not managed to find a definitive source of reference for this, but it appears to be around the SFr75 mark. So if the green customs sticker on your package indicates a value of SFr75 or below, normally it won't be processed by customs at all.
I would say this is a rule of thumb, and certainly not guaranteed. Swisspost may chose to open your package anyway to verify that the contents and a possible invoice match that of what is declared on the green sticker.