This is the classic WoW version of my Travel Macro that I use.
/cast [mod:shift]Swift Brown Ram;
/use [swimming,noform:3]Aquatic Form(Shapeshift);[outdoors,noform:3]Travel Form(Shapeshift); [indoors,noform:3] Cat Form
Obviously you wanna switch out the Swift Brown Ram for whatever mount you want. It should be smart about travel form and aquatic form. You need to shift-click to mount. Indoors it puts you into kitty cat, so you can dash or whatever.