Lucas usually responds the first time I tell him something, but if he doesn't give me any reaction, I'll go over to him, put my hand on his shoulder or head and repeat what I said to make sure he's got it. He might not want to do what I said, but at least I know he's paying attention and I can encourage him to comply without threats (most of the time.) He's really a focused little man though! Yelling doesn't make a difference, since I find that if he won't respond it's because he wants my attention instead of my instructions, which is easy enough to do, as long as I'm paying attention and notice. Lilia is still a little young to be following directions, IMO - sometimes she simply doesn't know what I'm talking about!
I'll NEVER do the counting thing, sorry. My neice is counted-to by both her parents & grandparents and I don't see any positives in it. First, they counted to three, but when she knew they still didn't take action after three, they counted to five. Now, she's nearly 4yrs old & they're counting to 10! I mean, geeze, where does it end? *Why not just take action after you tell them the first time and not threaten them at all?* If they learn that you're serious the first time, they'll be likely to comply the first time! It doesn't happen overnight, but I'd rather put forth the effort in "helping" them do what I say rather than let them grow up thinking that threatening other people is the best way to get them to do what you want.
I don't count to my niece when I'm babysitting her and I get a response on the first request b/c she knows I mean it ,even though I'm not going to physically punish her for noncompliance. If I tell her it's time to put her shoes on to go home and she ignores me, I'll take her hand, lead her to her shoes, sit her down & put them on her feet. No punishment needed, I just show her exactly what I meant & I remind her that next time she needs to do what I say WHEN I say it. It's a matter of establishing authority thru trust, not thru fear.