I pulled some building foam out of a dumpster some builders were using. It's off-white and about 2" thick, with paper glued on both sides. I cut off the paper, used a surfoam tool to finely grate it, and have been making large batches of scenicking foam. I dye the batches with craft store colors, which are very cheap, to make colors not otherwise available in the industry. (Sage, chamisa, pinon, one-seed juniper, Fremont cottonwood, New Mexican olive, and so on). Note: after the foam dries, I nearly always dye it one more time. I found a display in Home Depot of bits of blinds--the vertical kind for patio doors. The texture of the pieces is actually identical to N scale "coyote fencing," which I'm looking forward to building. I make terrain out of left-over chicken-wire and paper mache, which I make myself from newspapers, flour, and water. I use cheap plaster-of-paris instead of expensive modeler-type stuff, and I use generic white glue instead of "scenic glue." Wood for building layouts is an expensive proposition, but one could approach builders at any site under demolition. Old lumber from houses built 100 years ago is still probably better quality than the wood you can get these days in the store. One can also find wood in dumpsters. Many people tear down structures or build things and just throw away the wood. Try a dumpster by a furniture-making shop: these can be gold mines. If you see a pile of used lumber gathering weeds by someone's house, stop and ask if you can pick through it. I found 24-gauge wire was expensive to buy in rolls, and I needed a lot of it. So I began using telephone wire. Just remove the outer sleeve and start untwisting. I don't buy supplies from a major hobby retailer unless I have a 40% off coupon in hand--because the giant hobby box stores have already artificially inflated their prices 40% above suggested retail price. It's cheaper to go online, price-compare, and pay the shipping.