When writing jQuery code, there are a number of things you can do to get better response times from the client.
These tips are useful when you are doing heavy scripting on the client. If you use jQuery only for minor manipulations, then the user will probably not notice the difference, so these can probably be better considered "best practices" than essential time savers.
However, if you train yourself to always follow these tips, then your web page will run just about as fast as it can, and will probably not need to be improved.
Every new release of jQuery is better and faster than the version before it. When you are starting a new project, you should always check to see if there is a new version available.
A way ...