Look at your wrist in natural light and look closely at your veins. If they are blue, you are cool toned and if they are green you are warm toned. You can also use the jewelry method in which you try on silver jewelry, then gold jewelry. If silver suits you better, you are cool toned and if gold suits you better, you are warm toned. If both silver and gold look great on you or if your veins look both greenish and blue, you are neutral toned.
If a beige shirt look better on you thank a white shirt, it means you have a warm skin tone with yellow undertones
Thanks, that really helped! I never heard the vein method before. That's kinda cool! :D