Tuning
Three years ago I purchased a "Loos Rig Tension Gauge" from Boat US (West Marine handles them also). There are two basic models (Reg & Pro) with the expected difference in cost. The Regular serves me quite well. Appropriate tension values are given for various cable sizes as well as a gauge provided for accurate size determination. I use the recommended tension settings provided and adjust twice a year (had no reason to adjust a third time): once right after mast raising and about a month later. Using these settings really improved my boat's performance (speed, ability to point and handling). I am quite satisfied with both the ease of adjustment, the fact that I have taken the guesswork out of adjustment, and the results of my endeavors. I heartily recommend this gauge and this method.