Don't use a regex if you don't have to PHP has a rich set of string manipulation functions - use them! BAD: GOOD: BAD: GOOD: Use References if you are passing large data structs around to save memory There is a tradeoff here. Manipulating references is actually a bit slower than making copies of yourdata, but with references you will be using less memory. So you need to determine if you are cpu ormemory bound to decide whether to go through and look for places to pass references to data insteadof copies. Use Persistent Database connections Some database are slower than others at establising new connections. The slower it is, the more of animpact using persistent connections will have. But, keep in mind that persistent connections will sitand tie up resources even when not in use. Watch your resource limits as well. For example, bydefault Apache's