l usually just recline my passenger seat and stick em in that way but that only allows for ONE passenger and he/she must sit BEHIND me when i'm driving l was wondering if there was a better way to carry my boards in my jeep. l would just put them in the back but my longboard sticks out the side of the car.
l should also add that the racks that work for most hard top sedans/suvs/other cars in general do not work on my jeep.

get rope and strap to the roof

They make roof racks just for surfboards.

put them on the roof. they have specialized roofracks for surfboards. the real heavy duty hard ones and the soft racks that you can take off. go to a sports store, surf shop, or internet and get some racks. the soft onse are cheaper cause you can take them off of ur car. l hope this helps

http://cardomain.com/ride/3110799
http://ridershack.com/surfboardrackssurfboardautoracks-c-216_92_183.html?page=all&sort=3d&gclid=CNnxp8rOiZUCFRJxxwodcUh4cw

l guess u have a rag top. The first link l think only has racks for hard tops. l imagine it will take a little ingenuity, but u should be able to rig a rack system to ur roll bar & tail gate (may have to take of ur spare tire). But l am sure it can be done. l found those two links in five minutes on Google ''surfboard racks jeep Wrangler''. ( know l have seen surfboards on top of jeeps, l just never paid any attention to how they were rigged.) Good luck.