Faking VectorsLevel: Beginner This is a really old tut
Open your image in PS, you can use the one I'm using. Right click & save as.

Go to
Filter -
Artistic -
Cutout - and use settings below or adjust until you get a good vector look:

This is your finished result below:

Here is another finished one and if you have the Dreamy FX Filter & Dreamsuite using soft focus you can give them a really nice effect.