Subscripts and superscripts are denoted by _ and ^ respectively. Thus "x squared" will be written x^2.

Curly brackets are used for "invisible grouping" and round brackets for visible grouping. Thus we would write a fourier component e^ikx, assuming the reader is quite intellligent, or e^{ikx} if we wanted to make it really clear that all of i, k, and x were in the exponent, and e^{i k x} if we needed to make it clear that i, k, and x were all separate symbols, rather than a single variable named "ikx".

Greek letters and special symbols are named with words starting with a backslash, like \omega and \Omega for lower case and upper case Greek omega, \otimes for the tensor product symbol, etc.

This is a minimal but pretty much sufficient set of conventions.