Concrete is one of the most popular materials for crafting today, it’s minimalist, durable and with industrial chic. To make these simple and beautiful concrete vases you’ll need concrete mix, plastic bottles, pliers, scissors, a marker. Using a marker, trace a line around the larger bottle and cut around the line. Do the same with the smaller bottle. Mix the concrete and fill the larger bottle, roughly half full. Push the smaller bottle into the concrete mix until it almost reaches the top. Let the concrete set for 15 minutes and remove the outer plastic bottle. This can be a bit of a pain if your bottle is thick. Cut the rim of the inner plastic bottle to the same height and then the concrete. Fill with water and add flowers.