Depending on your cell type and the type of EVs you think of there may be different methods. 

In experiments where DU145 human PCa cells were stimulated with EGF extensive membrane blebbing and large oncosomes were noted:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2853876/pdf/nihms115499.pdf

y. A recent study has demonstrated that depletion of specific ESCRT-family members can alter the exosome protein content and the rate of exosome release from cancer cells.

http://jcs.biologists.org/content/joces/126/24/5553.full.pdf

Also have a look at:

http://www.gene-quantification.de/minciacchi-et-al-exosomes-cancer-2015.pdf

Dear Till, thank you for the suggestion. 

Interesting