Vertical wheel move
If you want to quickly move your items to another track you can use this action. If time selection exists and selected items are inside it, just the part inside the selection will be moved to another track.
Align items to markers
You can use this action to select multiple items on track and align them to markers inside the time selection with one click or shorcut key. This can be extremely helpful for syncing footsteps or gunshots to events in video.
Change Default Fade
With one click of a mouse you can modify default fade setting for new and already existing items. REAPER has a bunch of default fades available, but changing them is not something you can do in one step. This script changes that and allows you to be more efficient.
With this script you can change gain on multiple items using your mousewheel and desired modifier key (ALT,CTRL,SHIFT...). If no item is selected then gain will apply changes on item under mouse cursor. If more than one item is selected gain will be changed on all selected items. One drawback of this script is number of undos needed to restore original value.
It's the fastest way of editing audio there is. Use position of your mouse cursor to determine where fade or cut should be applied. It is improved version of Pro Tools editing workflow. It will dramatically speed up your process and once it gets under your fingers you'll never edit any other way.