You can leave out tuna or salmon. These foods have strong orders. You can also call your spca and leave a lost report with them. Also go in and attach a picture of your cat to the report.
You can also leave out on your porch something that smells like you and also that something smells like him, like his litter box. Talk to neighbours, put up posters, put an ad with picture in the paper. Check sheds, under decks.