Alternative to wonging
Rather than wonging, it is also possible to get away with the other extreme — to use bet variation, and lots of it. A card counter might be able to get away with one hand of $25 on the worst situations and have two hands of $500 or more on the best. In casinos where bets over $500 attract too much attention, you might be able to get away with $25 to $400.
Bet variation is tolerated better now than it was decades ago Perhaps this is due to the increased number of Asian customers in casinos now. In Macau and other locations in Asia, huge bet variation is the norm; if the table limit is 10 to 2000 in local currency, most customers seem willing to bet 10 for a starter and progress to 2000 if they hit a winning streak. If casino employees see enough bad blackjack players use huge bet variation, then a card counter using big bet variation can blend right in.
The trick to getting away with big bet variation is to do it in other than a mechanical, by-the-numbers way. For example, you might occasionally pop out a big bet on the first round after a shuffle. If you are going $25 to two hands of $500, for example, you might sometimes bet one hand of $300 or more on the first round. If you bet $300 on the first round, then you might go up to $500 or drop to just one black chip on the second round, depending on the count. Cutting back from $300 to $100 does not seem to attract attention. If you had bet only $25 on the first round you certainly would attract attention betting $500 on the second round!
Try to avoid any sort of a pattern. For example, if you realize that for the last ten minutes you have been betting only one or two green chips each hand because the count has not gone high, you might pop out eight greens on the first round after the shuffle. Your expected value is negative on that one bet, but it buys you the ability to bet eight or more green chips on the next good count. Do not use bet variation in a mechanical manner. If the count calls for a big bet, just grab a handful of chips and place them in the circle. If you want to bet $500 and you are betting in all green chips, for example, you may actually have $500 out there, but if you did not grab exactly the correct number of chips you might bet $475 or $525. People do not seem to pay as much attention to how much you bet as how you bet it. You would probably get more attention carefully counting out $400 than by quickly grabbing a handful of chips that happens to total $525.
A side benefit from betting odd amounts is more dealer errors. A drawback is game pace is slowed by odd-amount payoffs on naturals, and the errors that go against you. Bet what you can get away with rather than trying to bet an optimal amount that depends on the count. If the count is negative, try to bet the least you can get away with. If you have an edge, try to bet as close to the optimal amount as possible with the constraint that you want your bet size to look natural to whoever is watching.