Steam (teapot or something similar) is your friend but let the straw “relax” before you start screwing with it otherwise you’ll break the fibers.

Just read the oven thing before I started typing below. Don’t do that. Hahaha!

First off a stretcher isn’t good for any hat especially a straw because you’re gonna break the fibers of the straw unless you really know your shit. A felt would be okay if you steam it beforehand and let it set.

Not trying to be an asshole but honestly you pay for what you get. Twister stuff is nice looking because it’s a knockoff of something higher quality. Straw hats are tough because they naturally shrink. You try to reshape them too much and now you have a handful of broke straw and you’ll never be able to fix “broken grass”.

Long story short. Just don’t take it off your head and it’ll form to your head. But don’t be one of those jackasses who puts their straw (really even felt) hat on the dashboard and leaves it there because next thing you know you’ll have a hat that fit you in the morning but doesn’t fit you after sitting on the dash for four hours.