I wouldn't worry too much about TM. I suggest just leveling up as quickly as you can by doing quests, killing monsters or doing Chaos Tower. Fiesta is also a good way to earn some exp and TM. You get Fiesta Marbles from the monsters at Fiesta as well, 5 marbles can be exchanged for a Fiesta Box. Fiesta Boxes contain myshop drills, potions and resurrection scrolls. The reason why those players have high TM is usually because they AFK drill. Myshop drills give a lot of exp/tm per excavation in comparison to normal/in-game drills by the way, so if they use that, they get a lot more exp/TM just by AFK drilling.
Edit: You need 90 DA to drill without wasting your drill, you wont get "No Item Found" when drilling. You'll always either drill up an item or don't drill at all (you get squiggly lines).