whats the BEST window flashing?

I have been using the sticky tape butyl stuff 9" wide. Problem is even on clean perfect typar paper it comes loose very soon after install. Whats it lool like under siding after 10-30 years?? Is it as curled and unstuck as I see in a couple weeks uncovered??

I wonder of using the aluminum solid stock since anywhere you drive a nail you dimple it in and water is sure to follow. How close to a window do you nail vinyl siding??

Some guy posted a long detailed post on flashing the windows complete with alot of photos,,,any body know where to find it??MY search came up empty!!

What is best product and methods for flashing vinyl windows with nailing fin and using vinyl siding??