I don't know if anyone knows this already or not but I'll still post it for those that do not,
Say for example you make 2 new channels in a new document. on one channel you have a white square and on the other you have a white circle. normally to select the contents of one of the channels you would have to ctrl click but instead press Ctrl +Alt+ 4 to select the first channel you created(the one with the square) and Ctrl +Alt+ 5 (to select the white cirlce in the second newest channel) ..*I think this shortcut can be used up to at least 9 channels?**
Say for example you make 2 new channels in a new document. on one channel you have a white square and on the other you have a white circle. normally to select the contents of one of the channels you would have to ctrl click but instead press Ctrl +Alt+ 4 to select the first channel you created(the one with the square) and Ctrl +Alt+ 5 (to select the white cirlce in the second newest channel) ..*I think this shortcut can be used up to at least 9 channels?**