My dad was involved with diagnosing and investigating things like this, electronic harassment and whatnot. There are so many methods that are used, I would first search online for similarities and, in general, the many types of harassment that are used to subject others to this form of harassment.
As far as using only the mind to perform attacks, that would be far less common. That would also involve a lot of training. Technology is available that allows almost anybody the means to do this, so no special training would be required, and it would be quick and easy.
Bug detectors, magnetometers, UV light detectors, microwave-range detectors are readily available. But again, if transmissions are in burst mode, it would be difficult to track. Millimeter wave and higher frequencies are not as easily detected [using commercial detectors]. Voice to skull is also tricky. My dad did not find a way to easily stop that. The principle is simple, and pretty much anybody can do it.
Unless someone is the target for no end reason (military secrets, political, etc), they may just be practice for the other party. I’ve seen people mention this, so if someone just wants to mess with you, there is a lot more trouble involved. Look at the living environment first.
Apartments, townhouses, and other close-proximity housing allows for living right next to a harasser. This stuff goes through walls, so close proximity would be an issue. Sweep your area for bugs and other items that look out of place. Some could be re-transmitters. Windows facing certain things? Line of site also allows for attacks. Keep blinds and shades drawn. This pseudo-hiding may help, but body heat, etc. can still be detected if they are close enough.
Is full shielding of the area out of the question? Some people advocate removing all electronics. If you feel safe knowing what your devices are and that they have not been compromised, Shawn William Byrd recommends using tons of them. Lights, tv’s, computers, wall transformers, etc. all put out fields and can help scatter incoming waves.
Get some personal field devices. SWB Instruments makes things such as this for relaxation and clarity, and also to boost the natural, safe fields that are normally present. Don’t believe the sales pitch from other companies that any of their devices can “block” or “shield” you. Usually, the ones sold do not have a field strength anywhere near what is needed for practical blocking, especially for directed attacks. Sure, they can be made that way, but you can’t run them on batteries. Running them 24/7 would probably draw the attention of the FCC, anyway. Probably could combine a detector that turns one on for any length of time, though. Gives me an idea…
I would also eat well. Eat all manner of things in large variety – vegetables, fruits, nuts, pastas, fish, and steak. This helps maintain balance in both body and mind. Humans are made to consume all things, and we are at peak performance with a full complement of elements. The vitamins and minerals from food are far better than supplements. For instance, the iron in beef vs pills, gram-for-gram, is more than 20 times stronger, and it is also readily assimilated into our bodies. Vegetarians have a moral thing that I don’t understand, but I also give respect to the things I eat, and appreciate their benefits to me.
Having a healthy, clear head goes a long way to provide mental fortitude to bear and persevere.