Question: How can I prepare my shoes before painting them?
Options:
Remove the laces and clean thoroughly with acetone over any area you want to paint making sure to not touch any area you will be painting with your hands to keep the oils from your hand off the shoes.  Then after allowing the shoes to dry apply painters tape to anywhere you want to protect from painting.
Remove the laces and clean thoroughly with acetone over any area you want to paint making sure to not touch any area you will be painting with your hands to keep the oils from your hand off the shoes.  Then after allowing the shoes to dry apply painters tape to anywhere you don't want to protect from painting.
Answer: Remove the laces and clean thoroughly with acetone over any area you want to paint making sure to not touch any area you will be painting with your hands to keep the oils from your hand off the shoes.  Then after allowing the shoes to dry apply painters tape to anywhere you want to protect from painting.