OK so I have had my HTC Mozart WP7 for a few days now and am really enjoying finding out and using the new OS, and this article from Pocket Lint is a great place to start for tricks and tips for Windows Phone 7.
I particularly like and have found useful
10. What are the dots? - Whenever you see three dots at the bottom of the screen, that's a menu for more options. In photo playback for example, it will give you the options to delete the image or perform a quick upload.
32. Auto save your images to SkyDrive It's always a good to keep a backup of your pictures, and Windows Phone 7 comes with SkyDrive which lets you do just that. In steps the auto upload to SkyDrive option. If you got confused the first time it asked you when you went into the pictures area, don't panic, you can re-enable it via the Applications page hidden within Settings. Go to Settings, swipe to the left and then scroll down to Pictures & Camera. In there you'll find the option to set the Auto Upload feature on.
48. Finding more symbols on the keyboard. The keyboard is fairly comprehensive and simple to use, but it can't display all the symbols you might want at the same time. If that's the case press the "more" arrow to the left of the screen to reveal more keyboard options. Incredibly useful if you email address uses _ (took me ages to find this)
thanks to @stevecla1 for the tip