Cell cycle selection
Depending on the stage of cell-cycle you are interested in, people often use the size/morphology of the cell as an indicator. Then you select cells with a cell sorter.

Another option is to specifically tag some cellular molecule that can give an indication as to the relevant stage and then sort the cells based on the tag. This does not necessarily have to be cyclins - for example if you are only interested in S/G2 you could tag the DNA or maybe histones.