Don't worry too much about making combos. Serve tables as quickly as you can and survive for ten minutes. You can mess up to 4 times before it's game over. The achievement will pop up as soon as the 10 minutes are up.
Some ways of stalling:
Stay in the upgrade screen for the entire duration, it's only ten seconds, but if you are really having troubles, it could help you out a bit.
The following option is more luck than skill, but if you manage to get the podium upgrade every single time you can upgrade, take it. Once you max out at level 4, stop serving people and stand beside it. The hearts that the podium replenishes means you don't have to worry about patrons leaving, but again, it's unlikely that you'll get the podium upgrade every single time.
Edit: Once you get the achievement, you can also get the "There’s always tomorrow Flo" achievement by leaving your controller alone for about 2 minutes. People will get upset and leave, dropping your star rating almost instantly.