Assuming that you have a product people will purchase and your customr service is good enough not to gain complaints, you can use this method.
People like freeness. Getting something for nothing is the greatest enticement. Even if what you are giving away is worth the price you are charging, the word 'Free' is the key in the sentence.
For example; "Free drink with every order." The drink could be water and syrup with ice. It's free. The cost of that bottle of syrup, of that ice and cup will be made back many times by increased lunch sales.
"Free gift with every purchase." This is a bit more tricky only if you don't know the incredible bargains you can get when you buy an assortment of goods at an auction/foreclosure/liquidation of another business. The 'gifts' could be anything; from salt and ppper shakers to locks, whtever it is you've gotten in bulk from that auction. If you become a 'regular' at the various venues; you will learn what and how, and be able to buy a great deal of stuff you can also sell; but it is that 'free gift' which gets th customrs into the store.
Often people buy things in bulk, a dozen drinks, a ten pack of snacks, common items. By giving a free gift with these purchases you will get the business; i.e. free bottle opener, free dip, whatever.
If you sell stationery a free pen with a purcase gets your paper off the shelves. Free hangers for clothing, if one buys a certain amount; anything that is free that tends to 'match' the purchase will get people patronising your business as opposed to a competitior.
Once you've gotten the customrs into your place of business, try to keep them with excellent customer service.
Always remember, it is easy to get someone inside once, it is not so easy to get them to come back.