You can use your garden hose to help lay out the borders of curved areas for gardens, flower beds, paths or small ponds. Just lay the hose along the proposed edge, check it for position, then mark out the curve by using a garden spade along the edge of the hose.
Making perfect dovetail joints can involve some shop practice, so consider starting out with a less-expensive jig that is designed for making only one or two types of joint styles. Then you can later work your way on up to the more expensive and versatile jigs that will let you make up to four or more styles of dovetails. With any dovetail jig, try to avoid using a router that is very light; heavier routers will produce crisper and cleaner cuts.