Hends Lead Wire will help you to add weight to your flies. Just wrap it on the hook shank and you will get a nice profile without leaving spaces between wraps.
The lead wire is widely used for adding weight for nymphs, wet flies, lures and streamers. It is cheap and handy. Recently more and more countries are asking for non lead weight to be added to fishing flies. Lead is known as a toxic metal and is damaging the environment. More expensive but more heavy is the tungsten wire. Be aware about regulation in your fishing area.