Depending on what industry you are in you will see methods people get paid and some work better than others depending on which one of those industries you are in and what you can get away with.
For example, if you are a self-employed electrician you may go to someone’s house do a couple hours of work and wait for payment either in cash or by cheque.
If on the other hand you work in the building trade payment will generally be made in instalments unless you are a particularly trusting building company that is happy to wait until something is built before asking to be paid.
Another method increasingly used these days and almost always used by software companies is the monthly payment option.
There are even some sectors such as education where the payment terms are 100% up front. This may be the best way to get paid of all and removes 100% of the risk.
All the other options carry some degree of risk with the payment at the end of the project by far the riskiest. Whichever method you choose, check the history of your prospective client carefully if you don’t want to end up having to chase them for debts.