Is there a general rule regarding giving consent to search?
There is nothing that prohibits the police from asking for consent to search anything, person, place, automobile, purse, bag, etc. However, you have the ABSOLUTE RIGHT to say no and refuse consent. If they believe they have enough of a lwaful reason to search they will do it regardless of your refusal. You have nothing to gain by consenting. The police might say thigns like “if you have nothing to hide then why not?” or “I’ll just arrest you and search anyway?” or “If I find something I won’t arrest you.” While it is very scary to be confronted by one officer or several of them, you have the ABSOLUTE RIGHT to refuse consent. If you consent and they find anything illegal or evidence of illegal activity it can be used against you in court. If you refuse and they search you anyway, there might be a legal basis to suppress the evidence.