Myrrh is extremely viscous, and therefore more difficult to use. With time it may solidify. Gently warming the oil in the hands before use may help (takes patience!), or you may need to warm in a water bath.
Warm Water Bath: First, place the oil bottle in a bowl set in a pan of warm water (or double boiler) with enough warm water to affect the temperature of the oil, and avoid any possibility of allowing the water to get into the bottle. (I put my bottle in a ziplock bag and make sure it is standing upright.) Unscrew the cap slightly to accommodate for expansion while warming. Allow it to warm for about 15-20 minutes, replacing the water as needed if it evaporates. Continue warming until you get the oil at the right consistency to work with. Different oils take varying amounts of time to liquefy, and this somewhat depends also on how solid they are and their ability to soften. You may also want to use a pipette to help dispense.
Speaking personally, I'd use a rubber bulb/glass pipette that screws onto the bottle. I am aware that I need to be careful not to let the essential oil get on the rubber, so I'd make sure to wipe the rim of the bottle clean before recapping, and I'd not let the bottle tip over.