I've been playing for around 6mo and counting for about 3. Here are a few of the mistakes I've made that may help someone else out:
Trust your system: I started out playing Hi-Lo but struggled with the TC conversion so I switched to KO. The KO book tells you when to bet more and when to take insurance. There were several instances where the count indicated it was insurance time but I had it so ingrained in my head that insurance is a sucker bet (or it was right on the line and I wasn't confident in my count) that I didn't take it; sure enough, dealer had bj all but once when the count indicated. The one time they didn't, the down card was a second ace.
Side note on insurance, check your cards first. Last night I was playing and the count was so high that when the dealer showed his ace I promptly put my insurnace bet out there without checking my hand first. Sure enough dealer had blackjack. Unfortunantly so did I. I pushed instead of getting paid even money on my big bet.
I suspect I need to check my cards all the time for cover sake anyway. If the dealer shows an ace on the first hand I don't even bother to look before waiving off insurance. If the count is close I see how my cards impact the count before making a decision and obviously in last nights case my cards couldn't bring the count low enough to make insurance a bad bet so I didn't check then. A watchful pit could pick up on that pattern.
Quit when the playing conditions deteriorate: I've learned enough to not put win/loss limits on myself but I tend keep playing in less than ideal conditions. Where I play they cut the double deck in half. A full table of 7 players only yields two rounds. It's a waste of time and money. Pay attention to being hungry/tired and know that those conditions will deteriorate your play.
Have a plan: Know what you are going to bet at a given count. Know at what counts you are going to change BS. Stick to the plan. I've wasted a lot of money\opportunites waffling on how I should play each hand at extream counts.
I hope this helps someone out there.
Thank you to everyone out there who has made this such an outstanding forum.
b