3. Wooden crates and pallets as open shelving
Wine crates, sturdy fruit boxes and clean pallet wood make genuinely good shelving, and this is the repurposing project most likely to produce something that looks bought rather than salvaged — provided you do the finishing properly.
Source them free. Wine merchants and bars often give away wooden wine crates, greengrocers have fruit boxes, and pallets are frequently available for collection, though only take ones marked HT, meaning heat-treated. Pallets stamped MB were treated with methyl bromide and should never come indoors.
Preparation is the difference between furniture and firewood. Remove all staples and nails with pincers, then sand thoroughly: 80 grit to knock off splinters and rough edges, then 120, then 180 for anything you will touch. Wipe with a damp cloth, let it dry, and finish with clear matt varnish, a wood oil, or paint. Unfinished salvage wood sheds dust and splinters for years.
Then assemble. Two or three crates stacked on their sides against a wall make an open bookcase; screw them to each other through the adjoining sides with short screws, and — this matters — fix the whole stack to the wall with an L-bracket at the top. Unsecured stacked crates are a genuine hazard with children around.
Single crates work as under-bed storage on castors, a bedside table, a hallway shoe box or a planter for herbs with a liner and drainage holes drilled in the base. Mounted individually on a wall, they become cube shelving for a fraction of the shop price.
Check fruit crates for pesticide residue by washing them thoroughly before anything food-related, and avoid using them for anything damp indoors, since thin softwood warps.