Check the most common places. Then check like the bathroom, parents room then kitchen. If not found look in the basement if not found in the house go outside and look not in ur yard go to the most recent places u went to. Then if not their look at the places u went the day before u seen u cannot find it then if u can't find it go to the police station I had to go their they helped me with my phone I had lost it this random guy in the streets had it.. Hoped this helped!!!
What kind of phone is it? If it's an iPhone use the finymyiphone app and if it isn't keep looking and if you cannot find it, go to your provider's store and see if they can do anything.
oh crap call it!!!!