Any tips on teaching PATIENCE to your toddler/preschooler?

First of all, parents have to practice patience themselves. Lead by example. What I do with my girls, when they get impatient, I just calmly tell them to wait. Simple as that. Kids are impatient by nature, I think. They want things now now now. But if they get used to the notion that not everything arrives or happens the moment they want it to, then they'll accept that and learn to wait. But I now sometimes, ang kukulit talaga at gusto mo nang sigawan haha! So I'll go back to my first point, that it's vital for the parent to demonstrate patience to their child, too.