I bought a new tent, that has guy lines with a plastic slider that you can use to adjust. I've never used these... When I went down the Colorado River, the tent I had didn't have one of these. How do I use, tie, stake, adjust, etc these guy lines?
Thanks in advance.

A knot called a tau taut-line hitch is often used to attach guylines to stakes. This knot can actually slide up/down the main guyline to increase/decrease the line tension.

Here is a site that has a bunch of pretty cool animations for drawing knots. Scroll down the main page to see the full list of knots. The taut-line hitch in the column farthest to the right.

The animation shown suggests that the first and second hitches (wrapped around the guy line toward the stake) are somehow overlapped, but I've never seen that done in practice. I was taught to use three inner hitches (toward the stake) for particularly slippery rope. For narrow rope this knot can be hard to untie, particularly after rain. If this happens, consider adding a loop to the last hitch (toward the tent) to make untying easier.

Here is another site whose drawings aren't so high-tec, but I like that they show the stake for reference.

http://www.isu.edu/outdoor/knots.htm

Some tents come with cheap polypropylene rope that doesn't take knots well. In that case you'd likely want to replace the ropes with better stuff - paracord or 1/8 nylon or dacron cord. Use a two half hitches knot to fasten the other end of the rope to your tent.

Also, if there is ANY chance of bad weather, make sure you've staked down all stake-points on your tent AND add additional guylines tied to storm loops on the tent fly or the top of the tent frame to help the tent survive high winds. I watched in horror as high winds caved in the side of my large Eureka family tent clear down to the ground - luckily the poles rotated at the joints, but most poles would have simply snapped. I'll NEVER face a storm without additional guylines. Here a link:

http://www.bicycletouring101.com/CampTentHighWinds.htm

Because I often camp with young Scouts, my preferred guyline rope is the bright orange paracord from http://www.countycomm.com , in hopes that the boys will see the lines before they trip over them (note the word "rip" in "trip" - that is a horrible word to tenters). Also, if the weather is good, I'll usually leave "optional" guylines unstaked until bedtime - just to reduce the chance of tripping.

Check out taut line hitches. They're a great knot to know. To answer to your question, you hook the loop over the tent peg so it just slides freely. You adjust the tension by holding the plastic thingy at right angles to the rope (or at whatever angle lets it slide freely) and sliding it towards the tent.

This makes the loop bigger, but tightens the line. You rely on the line tension to keep the line from slipping off of the peg.

Bear

The plastic slider is the key. The slider goes between the tent and the peg, with the loop formed by the slider going around the peg. The slider works because of friction, and can be adjusted easily up and down. It's ahrd to explain without a visual. See if you can get pics of your particular tent (or any other for that matter) already set up.

Just play with it a while, anchored between a fence & a tent stake, and you'll get it.

Like Malpaso said, form the thing as a largish loop, hook the loop on the stake. Grab the side of the loop that attaches to the fence (or top of tent pole, etc) near the stake and pull it taut. With the other hand, slide the slider UP the taut line until it can't go any farther.

Once you've got them all more or less steady, go around again and tighten all of them. Check them again if the wind comes up.

Sue