What's the best knot for securing a tarp? Or for guy-ropes in general. Should I just pull the cord tightly and anchor it to the ground or is it best to set it up as a guy-rope so that it can be adjusted and tightened if necessary? I'm not good with knots (understatement) and have been known to improvise with a slip knot on tent guy-ropes which - well - slip. Especially when it's peeing with rain as it was last time I did this and the ropes were soaked through and very slippery.