DIY - Homemade Gabion wall ie rocks encased in wire baskets and used as a retaining wall - creates a dramatic feature in a garden. No directions on link. Nice someone figured out how to landscape with river rock. I swear they grow!
Hedges are a necessary part of every garden, providing privacy, blocking wind or even buffering noise. But most importantly edges provide structure to your garden. Hedging plants are usually budget friendly especially if you buy them bare-rooted.