For glycosylation site enrichement, you can either use lectin chromatography (reversible) or hydrazide chemistry (irreversible).

We have just recently used both techniques successfully.

For phosphorylation site enrichment, several successful techniques have been developed including IMAC, TiO2, and SCX enrichment.

Mass spectrophotometry, immunoaffinity subtraction methods also go through the review attached, You can as well use some bioinfo online tools that predict the PTMS.

Fluorescence dye staining for phospho or glycoprotein is a choice of method. it easy to process, however, some problem can be found (according to my previous work)