Easy, cheap, and quick; my favorites. The only thing to buy is 2 pieces of 1/2 inch conduit. The only tool is a conduit bender which you can likely borrow from the hardware store or an electrician friend. The bender is not too expensive if you need to buy it. I've heard you can fill the conduit with sand and use a vice to bend it also, but I think this would be hard with poor results.
Step 1: Rafter Side
This is a 180 bend in the conduit.
Step 2: Measuring Length
Once you have the rafter side bent, hook it and measure down to a comfortable working level. You will need about 18 additional inches for the second bend. With my rafters, I measured down about 4 feet, so I cut about 3 feet off on each conduit.
Doing the math 1.5 feet rafter bend, 1.5 feet bike bend, 4 feet from rafter equals 7 feet needed from a 10 foot piece of conduit.
Step 3: Bike Side Bend
This bend is a little less, about 120 to 145 degrees. You can do a 180, but it is easier getting the bike on/off with less of a bend. Once you have the bend made, you can take some old pieces of bike inner tube and wire tie them on to protect your bike from scratches.
The bends from rafter to the bike should have the hook (conduit) looking like a letter "C" , NOT a letter "S". A "S" shape is not stable.
Step 4: The Second One
Duplicate your effort and make a second relatively similar to the first. Sometimes I use one, sometimes 2 depending on what I am doing with the bike.