The reason why people have problems is most likely they are giving attention to thoughts of either the past or what if's for the future, then coloring those thoughts with emotions. So, while everything is fine at the present moment, it is not fine for the one who is off on the trhoughts and heavy emotions attahced to those thoughts.
One helpfull thing ( there are more but one thing at a time) is to observe the breath. One is breathing anyway, so therefore simply observe the breath. What this does is helps to keep one in the present, and relaxes the mind. Rather than one being off on the thoughts, the attention is to observe the breath. It is further added to bring it to balanced breath, so if one notices that one side is taking in less air, then one can have the attention to take in the air from that nostril. This is a starter, there are more things to do One should also stop once they notice that they are going off on thoughts and come back to the present. I had deep experieces in TM, yet I am telling you that what is advised here is not superficial but part of something very deep Tanmay