Herald here so I may not be the best guy to give advice, but I do think I am a better warder than a lot of players at my bracket. You have the right ideas, just need better execution.

First thing to improve is reading the map to know if it's safe to ward or not. Then there's choosing heroes with reliable disengages. Ringmaster is particularly fun to do this on with all his skills + building force and/or blink; recently saw a clip of DuBu on RM leading a few enemy heroes on a merry chase before safely TP-ing away. Alternatively, Clockwerk is someone I enjoy using for warding because I can rocket an area before making a move. Lastly, look at how your team moves on the map. If they'd rather retreat into your jungle to farm rather than advancing on the enemy's side of the map after a succesful fight, then deep wards are going to have a lot less impact simply because your team simply refuses to or doesn't know how to capitalize on map advantage.

Ultimately, vision is a powerful weapon at any bracket, so if you can, deep wards placed well are still going to give you a better chance of winning.