There are things in this world you never learn. You either wish you never will, or thought you never would. When the topic concerns symmetry of molecules, I've used (and keep using) the good old C1 for quite some time without any hassle. Excuses for not exploring it have been many, but when I had to be assistant teacher in a course (KemiKS) which the Department of Chemistry at the University of Copenhagen offers, I had to sit down and buckle up. Visualising it in 3D proved to be the hard task, so I went on the web to find the symmetry@otterbein website. It has interactive pages where you can rotate around the molecules to get a good feel for where axis and planes are. It also includes a challenge so you can learn to use the flow charts that follows every book on the subject.
Now symmetrize a molecule!