If you have a really big SVN repository with thousands of files and a rather deep folder hierarchy, opening the Tortoise SVN commit dialog from the root of the hierarchy can take a little while. Waiting sucks but splitting up the commit in multiple commits just for not to wait sucks almost more.
A colleague of mine eventually got so annoyed about slow opening commit dialog’s that he found a way around:

• Open the commit dialog not at the root but somewhere deep down the hierarchy. This should be pretty fast
• Browse to the other folders with un-commited files and drag-and-drop them into the commit dialog.
• That’s it, commit your files.

Sometimes the really helpful things are also the really easy things!

If you have a lot of files to commit you still might be faster opening the commit dialog from the root, but if you have just a handful of files and you know the files, above method will be faster.