Keep it in collumn!
Check out this site for gin pole ideas. The trouble people get into raising masts is keeping it in collumn with the centerline of the boat. If it starts to twist, you can lose it.I lay my spinnaker pole (you could use an 8' 1x4 or 2x4) athwartships at the base of the mast and lash the ends to the lifeline stantions or the trailer. Then attach a halyard to each end. Using a gin pole with the trailer winch or led back to one of the boat winches, raise it slowly, knowing you'll have to stop midstream to untangle a shroud or backstay. Best to tape turnbuckles together to keep them from flopping, they'll crimp otherwise. I raise mine singlehanded this way.The easiest method is to have two people handle the halyards to keep the mast in line and help with the weight while the third lifts from the cockpit, but when you're short handed....