I like holes where the OB narrows on one or both sides of the fairway as it gets closer to the green. The longer you know, the more the need for accuracy. But I think you have to keep the OB at a reasonable distance from the basket. Shots that land OB should be the result of a poor decision, a poor execution, or both. It shouldn't be left to "luck" or chance, such as an OB line too close to trees on a main fairway route, or a basket that spits a putt that rolls OB. OB is generally the lowest point, like a road or a pond. So this can increase the chance that shots will land there and more distance should be given for close to the basket situations the lower it is from the basket. If OB is used next to a basket, I would think you would put it somewhere where an advanced player might make the putt half the time. Maybe around 35'. Then pros can limit the amount the OB punishes them, but it still takes a good shot. For OB near the edges of the fairway, a 50/50% chance of getting up & down makes sense as well. For OB around the green, you almost always see it behind the basket. If a player knows they can make the putt from the OB line, they can use this as insurance instead of having to face a tough decision. I think that having OB in front is more interesting. Then a player has to decide to lay up or go for it on the drive or approach. Then the player who runs at the shot and runs too far past has to again make a decision because if they go past this time they'll be OB and looking at a big number. In the end, I think it is situational. On an open flat course, some guidelines may work pretty well. But in more unique situations, some exceptions might actually add some flavor.
I agree with most of what you are saying here, but I think I need to clarify my point a little bit. I think OB should be at the closets 20ft ONLY when it isn't too expansive around the pin. For example, if there is a little pond 20-25 ft away from the pin but it is only towards the left edge of the green I would expect players to account for the type of OB and to either challenge the pin and take the risk or play it safer out towards the right and see if they can still get close enough for the bird. I guess the main point of questioning OB is to question whether it is fair for the player throwing good shots and one of the main thoughts that comes out of that is that you can still throw a good shot and land OB if you didn't take the OB into consideration, but then did you really make a good shot?
Can anybody think of a good way to have a bunch of artificial OB without rope or paint, both of which are time consuming and expensive? (I know roads and water and paths and whatnot, I'm saying where that isn't available.)