I tend to teach the down near to me first, by luring the dog into the position with a toy/treat. Once they are able to go down at my feet on a word command only I start using the command when they are away from me (usually if they are just freely sniffing). Because they understand the command to drop they usually down where they are without needing any further incentive.
If they initially run to me to go down then I would either a) have them do a send away to a marker that they would drop at (to get their reward). b) Throw treats/toy out away from me and get them to drop on the treat/toy. c) encourage them to walk backwards, then fold into the down. Any of these three things will get your dog used to dropping at a distance from you to get over the down at your feet thing. All these things have worked for me to get my dogs more confident at dropping at a distance from me.
Also, remember to go to your dog to reward it to reinforce them doing the action on the spot they were on, i.e. for dropping on your command. Also some dogs find waiting in a stand, or 'sit' easier, so they may respond better to either of those commands.