How to tie up the loose ends in knitiing.

So i am almost done with my lace shawl now. And I am a beginner. So I used 5 skeins of yarns instead of 4(as told in the pattern cuz I dont wanted to make it wrong as its a gift for my mil. And I just didnt want to take risks that I wont amend if goes wrong.) so now I am left with open yarn ends. And its getting difficult to weave as its a lace shawl. So anyone have any ideas of making knot. Mind you that they are in the back(wrong side) of the shawl. And its nothing but some knits and purls.