If you use an external flash you can use a bounce card to modify the light. Just cut a piece of white cardboard and attach it to the flash head with a rubber band as shown in the image.

But why not make a bounce card with 4 different reflecting surfaces on one card? Just use gold and silver foil, colored paper or similar material to stick it to the white cardboard as shown in the images.

DIY Bounce Wall for 99 Cents

DIY Camera Sniper Strap

Budget flash diffuser

MacGyver light stand

How to make a bean bag quick and easy

Build your own "Heavy Duty" light stands for less than 10 Euro

Macro studio in a bucket

How to make a golden reflector

How to make cheap sturdy poles for supporting lights, backdrops etc.

How to attach a cloth umbrella to a work light

How to make a 4 in 1 bounce card

DIY Macro Softbox for free

DIY Multiclip

Reflektoren selbst bauen - lohnt sich das?

Use a large sheet of white paper to bounce light into the shadow

Build your own sturdy, simple, adjustable light stands

No budget table top photography

Goldenes Sonnenlicht vom Reflektor

Silberreflektor Marke "Eigenbau"

Ready made bounce