Most of the time, the actors are in charge of their own wardrobe. Tell them to bring 3 choices for every one outfit that they need.
So if the movie takes place over two script days, and they need a different outfit for each day in the script, they should have 6 outfits with them total.
Wardrobe that is specialized, like a vampire costume or police uniform, is something you may want to ask about when the actor is auditioning. Possessing a specialized outfit that is needed for the project will sometimes bring more consideration to that actor for the roll
If they’re a really bad actor, the clothes aren’t going to change that and unless the roll is small, I wouldn’t put your production at risk for the wardrobe, but if it’s a close tie between two actors for a roll, and one has an outfit already, I’d go with the one with the outfit.
The rest of the wardrobe can be picked up at thrift stores, or discount clothing shops like Target or H&M. Have the actor pick up what they need and remind them that this is a low budget project and that we’re trying to keep expenses low so no shopping at Barney’s to find the jewelry piece for your 5 minute short film, unless they want to carry the expense.
And sometimes they do.
Sometimes actors need a particular piece of clothing to round out their personal acting wardrobe and it happens to be the same piece of clothing they will need for the shoot. So they don’t mind carrying the cost of the item because they are going to keep it afterward and use it themselves.
The same thing goes for props.
Actors usually have a number of props they have acquired through the many projects they have been involved with. You might also already have the props you need in your home.
Or if you know a nurse, and your movie calls for a nurse, you might want to ask your friend if she has an extra pair of scrubs and a stethoscope you can borrow.
If you do borrow, be sure to treat the clothes and props gently and to clean the items before returning them. They should arrive back in the lender’s hands in equal or better condition than when they left.