Treenoob, You can also just use a rated rope snap and climb on a closed system which is just the tail of your line tied to the ring of the rope snap with enough left over to tie a tautline or blake's hitch. A lot of people still climb with this system, it works well.
You just need to make sure that both ends of your line are isolated and not split by limbs to wherever your highest point of your climb will be, because you cannot pass a limb without retying your knot.
There will come a time where you will want to unclip your high line so while you are acquiring gear, get a lanyard of some sort so that you can tie in in the event of repositioning your climbing line.
Dave