iTunes 9 has been out for a little while now, so here is a collection of tips and tricks that are new in this version.

1. Nested rules for smart playlists

As well as the plus and minus buttons for adding multiple rules to a smart playlist, there is now an ellipsis button for adding nested rules. Whereas before you could only set it to match any or all of the rules, now you can make more complex rule combinations.

For example, you could set the first rule, then add two rules at the first nested level by clicking the ellipsis button and then the nested plus button. By then setting the top level to match all rules, and the nested level to match any rules, it will find songs that match both the first rule and either of the two nested rules.

2. Automatically Add to iTunes folder

iTunes stores all of your music inside the iTunes Music (or iTunes Media if you haven't had a previous version of iTunes) located inside the Music folder in your user folder. There is a new addition inside the iTunes Music folder called "Automatically Add to iTunes". Anything that you drop into this folder will be added to iTunes next time it opens, or instantly if it is already open.

This folder isn't in a very convenient place, so to use it properly you will want to drag it to the Dock or Finder sidebar, or create an alias on the desktop by holding Command and Option and dragging it.

Another great use for this is for copying music across a network to another Mac. Instead of having to go over to the receiving Mac and opening up iTunes to import the music, you can just drop the files in this folder directly from the sending Mac.

3. Organise the iTunes Media folder

The disorganisation of the iTunes Music folder really shows how iTunes has far outgrown its original purpose. Every time Apple has added a new feature, things have become more muddled. Up until now, Movies, TV Shows, Audiobooks and Ringtones etc. have been added as subfolders of the Music folder, which doesn't really make sense.

To fix this, you can choose “Organize Library” under “Library” in the File menu. In the window that appears, click “Upgrade to iTunes Media organization” and when you click OK, iTunes will sort out the mess in your iTunes Music folder. You will now have an iTunes Media folder, with subfolders for Music, Movies, Apps, TV Shows etc.

There is one reason you might want to avoid doing this however. Your next Time Machine Backup will probably take a long time, depending on the size of your media library.

4. Customize the column browser

The column browser in iTunes 9 is better than ever. You can enable it by choosing Show Column Browser from the View menu or by pressing Command-B. The new features that allow you to customise it are located in the Column Browser submenu of the View menu. You can position it to the top or to the side of the main music list, and you can choose which columns appear from Genre, Artist, Album, Composers, and Groupings.

Each playlist can also have its own browser. Apple have demonstrated this by adding a "Classical Music" playlist which has the Composer and Grouping columns, for those who group their music by Composer or Symphony rather than by Artist and Album.

5. Edit your iPhone's app screen

There is a new page for managing which Apps you want to sync to your iPhone and how you want to position them on your iPhone. When you have your iPhone or iPod Touch plugged in, just click on it in the sidebar and then go to the Applications tab.

It's fairly basic, but it's still loads quicker than organising your apps on the iPhone device. There are two major benefits: Firstly, you can drag and entire screen of apps in the list on the right to change the ordering on the screen. Secondly, you can hold Command when clicking apps to select more than one at a time and move them all together.

6. Different way to access the mini player

When you first download iTunes 9, you might think that the mini player is gone. Clicking the green zoom button in the top left now just changes the size of the itunes window instead of changing to the mini player. Now you have to hold Option when clicking the green button to get the old behaviour back.

Update: This appears to have changed back to normal with the iTunes 9.01 upgrade. If you liked the new 9.0 behaviour, simply use the following Terminal command to change it back:

defaults write com.apple.iTunes zoom-to-window -bool YES

7. Make Genius Mixes appear

One of the best new features in iTunes 9 is Genius mixes, a collection of ready made playlists that iTunes creates by analysing your music library. Unfortunately, it doesn't always appear right away. If you can't find Genius Mixes in the sidebar, choose "Update Genius" from the Store menu and it should appear.

8. The shopping cart is gone

If you had the iTunes store set up to add items to a shopping cart instead of buying straight away, unfortunately the shopping cart is now gone. It has been replaced by a Wish List, which works in pretty much the same way. Just click the arrow to the right of "Buy Now" and select "Add to Wish List". Also, in theory, all the items from your shopping cart should have moved over into your wish list.

9. Home sharing

The new home sharing feature allows you to actually share your music between computers, rather than just stream it across the network. This makes it a lot more easier to transfer your purchases between computers without having to use flash drives or email attachments.

When iTunes is open on other computers on the network, they will show up in the sidebar. Simply click on them, then choose any songs to transfer to your computer. This works with any media type including Movies and TV Shows, and it doesn't matter if the media was purchased from iTunes or not. On top of that, you can filter the list to only songs that you don't already have in your library, and you can set iTunes to automatically copy across any new songs that are purchased on the other computer.

However, things become a bit more complicated if you use multiple iTunes Store accounts (i.e. a different one for each computer). The iTunes Store doesn't have to be logged into the same account on both, but Home Sharing does have to be set up with the same account. If you find it isn't working, turn Home Sharing off and then on again from the Advanced menu. Then re-enter the iTunes Store account username and password, making sure you use the same account on each computer. Even though you only use one account for home sharing, you should be able to share songs purchased with either account, as long as both computers are authorised to play them.