For decades, I had trouble-free feet while hiking and backpacking.  Until this year, I did not bother to shop for boots that fit.  I ordered my size from mail-order catalogs and they worked fine. Then in 2005, I had my first problems with blisters while taking many long hikes in a row with Jim Smoak in the Teton’s.  I blamed it on my fairly stiff, heavy boots and replaced them with lighter, running-shoe type boots.  Then, in early 2007, I had different kinds of sore spots that rubbed raw and bled while walking no more than a mile or two when my feet were wet and wearing sandals, such as with canoeing and scuba diving.   Later in 2007, I went on a 6 day, 65 miles, 50 pound pack backpacking trip to Glacier National Park.  I did everything thing I could think of to avoid blisters, including taking new, thick socks and changing into dry socks 3 times each day.  Despite those efforts, I got big, trip-stopping blisters on the middle front of each foot the first half-day.                I asked some experienced long distance backpacker friends for advice.  Larry Horrell seemed to have problems similar to mine when he was through hiking on the Appalachian Trail.  He wore medium weight boots and carried a moderately heavy pack.  He got blisters quickly and repeatedly.  He did the best first aid he could on the trail and kept hiking despite the pain.  As some blisters healed in the trail, new ones would form.  He never resolved it and just sucked it up.                  “B” Townes also through hiked the AT, but took a lighter approach – wearing running shoes and carrying a pack that averaged as low as 20 pounds (with food and water).  His super-light outfit was only possible due to very tight planning: he had no sleeping bag, water filter, tent, gas stove or other backpacking staples; and only 1 quart water bottle.  He used a thin blanket, water tablets, tarp and alcohol stove.  Rougher  weather or terrain would necessitate a heavier pack.  “B” rarely got blisters, except for one bad stretch in Pennsylvania.  The few other times he got blisters, he did first aid on the trail and, like Larry, kept on hiking through the moderate but non-debilitating pain.  He developed major calluses that mostly protected his feet.                Bob Boettger, John Willardson and Chuck Forester have all taken week long collections of multi-day, long distance (10 – 15 miles) hikes in high mountains and reported only occasional, non-debilitating blisters.  They mostly follow the regimens outlined below.    Some of the classic pieces of advice seem to be trade offs.  Wearing a thin liner sock under a thick absorbent sock, to allow the friction to occur between the layers, is balanced by the extra heat, sweat retention and occasionally bunched fabric of the liner sock.  Keeping feet dry with heavier, water proof boots that exclude rain and dew is balanced by the greater retention of heat and sweat, and greater work of lifting them thousands of times each day.       The negative factors which seem to contribute to blisters are:  age – thinner and drier skin body weight pack weight distance / day days on the trail, or total trip distance heat  – weather, muscular action of hiking, friction between boot and foot wetness – rain, dew, stream crossings, sweat uneven weight distribution on bottom of foot   Do all you can to reduce each of the above factors.  Obviously, you can’t reduce your age, so be aware that will be an increasingly negative factor, and to improve your enjoyment, plan trips by reducing other factors – mileage, pack weight, cooler weather.    If some negative factors can’t be avoided, then reduce their effect: wear foot sole inserts to offer cushioning and build up arch to spread weight over bottom of entire foot rub hand lotion or Vaseline on feet   start early in the morning, go slowly and take frequent breaks at each stop, remove boots and socks to let everything dry out soak feet in cool water finish late in the evening.    If you still can’t reduce the negative factors enough to avoid blisters, then handle them quickly: cut open blister to relieve pressure & let drain cover with Vaseline or similar unguent pad with moleskin or similar 1st aid material cover with slick, tenacious tape – duct tape seems to work better than white first-aid tape try to continue hiking, since the pain may be manageable and even subside over time over several days the blister should partially heal and become callused, even under continued hiking pressure, possibly allowing you to complete the trip.    A bad day on the trail is still better than a good day in the office!