Here is a collection of 10 tips that are slightly more advanced than usual. They are aimed at those who want to become more expert Mac users - and of course those who think they already are experts... In general these tips will help you save time and effort when carrying out day to day tasks and hopefully introduce some concepts and applications you may not have come across before.

1. Download Quicksilver

This is really the most important pro app for Mac OS X. The principle of Quicksilver is simple, but it is amazingly powerful: Hit a hotkey, then start typing what you want to do. You can open an application. Send an email to a certain contact. Pause iTunes. Anything (more or less). But what makes this so incredible is that Quicksilver learns over time so you can get what you want faster and more efficiently with less and less effort. Head here for a more detailed explanation, or if you've got some time to spare, watch this demo video. Download it from the Blacktree site.

2. Get to grips with keyboard shortcuts

This may seem like a really simple tip, but far too often I watch supposedly experienced computer users take forever performing simple tasks like copying and pasting. The fact of the matter is keyboard shortcuts make everything easier, but not only do you have to learn them, you have to get into the habit of using them. There is a hugely extensive list here, but to be honest nothing will save you more time than getting into the habit of using shortcuts for quitting, closing windows, copying and pasting and switching applications.

For the more adventurous, you can create your own keyboard shortcuts in the keyboard and mouse section of System Preferences. And if you want to go even further, here are 10 AppleScripts that you can assign keyboard shortcuts to using Quicksilver.

3. Drag and drop everywhere

This is often a problem that comes from working in Windows a lot, where drag-and-drop doesn't quite have the same power. However in Mac OS X, you can use it almost anywhere. Dragging folders onto open/save dialogs will make it display that folder. Dragging text selections onto icons in the Dock does all sorts of useful things. And you can just drag files onto "Choose File" buttons in web pages.

4. Change hidden settings with Terminal commands

Often developers choose not to include some settings in the preferences of an application in order keep things nice and simple for the user. Luckily, they often leave these hidden settings accessible via the Terminal. Although this will scare off a lot of people, being comfortable with the Terminal is really useful and it's the best way to get a higher level of customisation and enable hidden features on your Mac. Luckily, modifying preference files is one of the easiest things you can do in the Terminal - just paste in a line of code and hit return. Simple! Here is a list of Terminal commands that will work with every version of Mac OS X, and here are some ones just for Leopard.

5. Download VLC

VLC is a multipurpose media player that can play pretty much any movie file you throw at it. While Quicktime will serve you for most needs, VLC will handle anything that Quicktime struggles with, as well as stubborn DVDs and VIDEO_TS folders. Download it here.

6. Understand the concept of packages

In Mac OS X, packages are just folders disguised to look like single files. In fact, almost every application is a package. To look inside packages, just right-click on one and choose Show Package Contents. Why would you want to do this? Inside application packages are all the files it needs to run. Once inside, you can tinker about and change things. Here's a previous tip with a collection of things you can do, including changing the unexpectedly quit message, the iCal alarm message and the layout of System Preferences.

7. Quickly kill accidently opened applications

If you are clumsy like me, you will often accidently click the wrong icon in the Dock. Or maybe you occasionally want to stop iTunes opening up when you plug in your iPod. If you are quick enough, you can just right-click (Control-Click) on the icon in the Dock and choose Force Quit. If you are too late, pressing the Option key will change Quit to Force Quit so you can close the unwanted application even faster.

8. Make rectangular selections (Cocoa apps only)

This is one of the best tricks for saving time when you are moving round chunks of text. If you want to select a column in a table or remove the numbers from the start of each line in a list you would normally have to go through every line individually. This can be hugely time consuming if you have a long list. To get around this, just hold the Option key while making the selection. Now you can draw a box around the stuff you want to copy or delete etc. and not worry about having to select entire lines.

9. Learn some AppleScript

Don't be put off by the idea of a programming language - AppleScript is about as close to normal english as you can get. AppleScript's real power is it's ability to automate repetitive tasks — in fact Automator is basically just a visual way to create AppleScripts. The best way to get familiar with AppleScript is to download some example scripts, try and figure out how they work, and then try and extend them or customise them for your own needs. If you are looking for scripts, I've written loads of tips that use a small bit of AppleScript to solve a problem.

10. Get comfortable using the command line

While you might be fine pasting a single line into the Terminal to change some hidden settings, you might not be comfortable actually working from the command line. I guess the whole point of Mac OS X is that it is a pretty graphical interface placed over the command line, but in reality some things are faster from the Terminal, and some things aren't possible without it. Learning about using the command line requires a whole tutorial in itself so I won't go into it here. O'Reilly have a great series of tutorials for beginners, and OSXDaily have a list of common commands.