There is no reason to be scared when you meet a new photographer, and no reason to think it is a dangerous job since I believe most photographers are good people. But prevent problems and be prepared in case that anything happen is always good.
One of the biggest mistakes models can make is to assume that all professional photographers are actually professional in their behaviour. It doesn't matter how wonderful and recognised is the professional works, it won't stop anybody who have a pervert mind. On the other hand, guys who photograph just as hobby are often more honest and safe than many celebrity photographers. We can't just assume or judge from appearances but every model should follow this safety tips, or any other safety method that works for them.
First of all, a good photographer, professional or not, will want see the model feeling relaxed, because if the model is tense, worried or afraid it will make the photographer's job more difficult. - I know there are photographers who like to verbally frighten models when they can't deliver the expect result or follow the photographer direction, as method to push the model to do her work. I don't want to discuss such methods now. What we all know is that when models are focused on their work with no distraction or worries they deliver a better job. - So be aware if the photographer who you are working with care about how comfortable you are for the job.
Tip number 1: Do your home work.
Whenever you are going to work with a new photographer, always search about him. Look for models he have worked with to ask about how is to work with that photographer. Try to find out if they are honest about payment, work method, safety during the work, if the photographer is not just a guy trying something else with the models, etc. The more people you find, in order to know about the photographer, the better. With internet it becomes easier as never before.
You also should be careful about bad comments. Often models talk bad things about a particular photographer that may be just a wrong impression the model had about him when working together. Sometimes a model can hate a photographer just because she was expecting looking better on the photos (when it wan't the project intention), or just because they found out the photographer is not a professional but a hobbyist. But it doesn't mean the photographer is actually bad. So we sometimes have to identify when the model is the problematic one and not the photographer.
If you don't find anybody who the photographer have worked with, don't be afraid to ask the photographer and then try to find the model's contact. Photographers know, our should expect, models to do their homework.
Tip number 2: Let always somebody else knows where you are.
At any work you do, it doesn't matter if it is in a home studio, location or professional studio, always let a friend knows where you are. Because in case you find out the photographer who hired you is a problem, have somebody near to come and pick you up is always better and will make you feel safer.
You can ask the photographer if you can bring a friend with you of course, but many photographers will say "no". Now, don't think the photographer is saying "no" because he is just an ass. Many photographers are as worried about their safety as their models. I would feel worried if a model show up with a body builder angry face trying to intimidate me just to make the model (his friend) feels safer.
An other issue happens when model's friend decide to help during the photo shoot, and try to give unsolicited direction to photographer and model, becoming a big distraction from the achievement that both model and photographer have planed for the shoot. It can also happen the model start to ask to pose with his friend who was not hired to the session. And when it happens the model is out of her focus.
The worst can happen is the model appear with her jealous boyfriend. Often boyfriends are ok about their girlfriends modelling until the day they see the photographer working. And some boyfriends can get aggressive.
Believe me, there are a lot of stories with bad ends because of model's friends in studio during the shoot. So try to understand when photographers don't want nobody else in their studio. But you always can ask for a friend who lives near where the shoot will happens, to be on your guard, or ask a friend to wait for you in a bar, cafe, park or shopping near by, if the shoot doesn't tale more than 2h at least.
Tip number 3: Contact a friend who knows where you are just before start to shoot.
The idea to let a friend know where you are, and inform them you are ok by text message or short call, is to alert him that something is wrong in case you don't send any message after 10 or 20 minutes after meet the photographer and after the end of the shoot. And he can call the police and help you if you get in trouble.
So you got a photo shoot and just before meet the photographer you contact your friend to let they know what time you will meet and that it is actually happening. When you actually meet the photographer you will talk about the shoot, the direction, know the space, plan some details, prepare the outfit and do the make up. This is the time you can know the photographer, see if he is serious about the photography work or trying something else. If you see the photographer is fine, just before the shoot you can send a message to your friend telling him that everything is ok. So he knows you are safe. Otherwise you can ask your friend to come and pick you up, if you feel you are getting in trouble.
Your friend, should also be informed when the shoot is planed to finish, and when you finish the work you should send a message to him to let him know it ended ok. If in case of delay don't forget to let your friend know you will finish 20, 30 or 40 minutes later.
But don't keep using the mobile, receiving calling or distracted with it during the shoot. It is really annoy for the photographer when the photo session flow is interrupted. Only in case of any delay for the end, tell the photographer you have to send a message to let a friend know you "will be late".
These are three very basic tips which I have given to models I planed worked with. Because often they ask if they can bring a friend and often models' friends in studio have being a problem. I tell them about these safety methods to make them feel safe and show them that I care on how they feel and I want them to enjoy the work with no worry. And as I can tell it seems to work for them. Then I hope it works for you too.