Shaun White Skateboarding

Once you unlock the ability to shape rails you also get the ability to have them lock onto other rails or objects. To do this, get on a rail and move it up or down towards whatever you want to connect it to and wait until the object you are shooting for has a green circle around it. Then let the rail finish shaping and you are done. I did this without trying but if you need to farm for it there are locations all over the map. You can reset rails by pressing and the rest rails count towards this as well.