Spammable Stealth

This macro will allow you to cast Stealth without being unstealthed.

/cast [nostealth] Stealth 

Spammable Shadowmeld

This macro will allow you to cast Shadowmeld without being unstealthed.

/cast [nocombat,nostealth] Shadowmeld

Spammable Stealth or Shadowmeld

This macro will cast Stealth if you are not stealthed and cast Shadowmeld if Stealth if on cooldown and out of combat.

/cast [stance:0] stealth 
/cast [nocombat,nostealth] shadowmeld 

Stealth and Cheap Shot

This macro will cast Cheap Shot if you are stealthed aor Stealth if you are unstealthed.

/cast [stealth] Cheap Shot; Stealth

Stealth or Vanish

This macro will cast cast Stealth when you are out of combat and unstealthed and Vanish when you are in combat.

/cast [combat] Vanish; [nostealth] Stealth

Gouge or Stealth

This macro will cast cast Stealth when you are out of combat and unstealthed and Gouge when you are in combat.

/cast [combat] Gouge; Stealth