Add a Keyboard Tray to a Besta Desk - IKEA Hackers
Amazon.com : VIVO Clamp and 12 inch Rail Set for DIY Custom Wooden Keyboard Trays (Tray Not Included), Under Desk Pull Out Slider Track with Extra Sturdy C-clamp Mount System, Black, MOUNT-RAIL02 :
How To Build a DIY Keyboard Tray • The Home Woodworker
Ergonomic Keyboard Tray & Drawer | Under Desk Support | Humanscale
Amazon.com : VIVO Large Keyboard Tray Under Desk Pull Out with Extra Sturdy C Clamp Mount System, 27 (33 Including Clamps) x 11 inch Slide-Out Platform Computer Drawer for Typing, Black, MOUNT-KB05E :
Functional DIY Computer Desk With a Hidden Keyboard Tray From An IKEA's Dresser - Shelterness