I like to approach the Eiffel Tower from Trocadero - look at it from above and then walk down towards it.
If you get the train from DLP get off at Charles de Gaulle Etoile and then change onto the metro for one stop (there is info in my Easter 08 trip report about which line to take - we did 2 separate day trips to Paris so i cant remmeber which day). Get off at Trocadero and as I say you can walk down towards the Tower.