General
⌘ ~ cycles through windows of the same app
⌘ + Shift + [ or ] will scroll through your tabs in most apps

Finder
⌘-T – New Tab
⌘-K – Connect To Server

Symbols

• Emojis & Symbols under Edit menu (⌘-^-Space) then technical symbols
• ⌘ (Cmd) – places of interest
• ⌥ (Alt/Option Key)
• ⇧ (Shift)