Hi Teloe! Welcome to the Forum, and to the iSecretShop platform!
Regarding your question above - it all depends on the shop in question. Different shops have different requirements when it comes to this, and different guidelines to adhere to in this case. If this is not clearly listed in the shop description/guidelines/scenario, I recommend contacting the schedulers and asking them - that way you will have the most reliable information, and you elimiate the need to guess and make assumptions.
It's the golden rule when it comes to questions about specific shops - when in doubt, ask the MSP that posted the shop. :)
As for tips and additional advice, I suggest checking out this thread: https://www.secretshopforum.com/thread/1/2/94/pro-tips-for-those-who-want-to-be-the-best-shoppers#post528