My cat went missing, what should i do?

My 4 year old cat Frodo has been missing for two days. I love him very much and just want to snuggle him. He is an outdoor cat, but usually comes to sleep with me every night. One night he didn't come. He hasn't come back for food either. He loves being outside, but this is not like him at all. I've gone looking for him everywhere and ive checked the spca and put up posters. I'm really scared and i just want him back, please, is there anything i could do?