Value averaging has you shift the balance of your portfolio over time, not the amount of contributions. So you can only do it if you have a portfolio holding both risky assets (shares etc) and some cash.
You start out by making a plan about how much you will contribute every month and at what rate you expect the share part of the portfolio to grow. Perhaps based on 20th century data you think an 8% growth rate is reasonable. Or alternatively if you know your desired final amount obviously you can work backwards to a desired rate from that.
If in any month the share part is falling below its expected growth path, you would put more money into it: possibly your whole paycheck contribution plus some from the savings cash account. On the other hand if the share component is growing "too fast" you would put all your additional savings into cash. So if your investments are doing well, you're not supposed to spend the excess money, but rather to put it aside into a dedicated cash account to top up your share component when prices fall.
In theory, this has the auto-levelling benefit of Dollar Cost Averaging, but even better: when prices are high, you'll automatically buy fewer shares, or even sell some; conversely when prices are low you'll buy extra shares from your reserve account.
If it turns out your estimate was unreasonably optimistic, and over your lifetime shares only ever average 3%, you'll end up with an entirely share portfolio, and a bumpier ride than you might have liked. If you have horrible luck and over your entire investing life shares return less than cash (which has happened, though not yet in the USA), then this will be worse than a standard balanced portfolio.
The original book Value Averaging by Edelson has a pretty good explanation of various cases, though I would say some of the examples are worked in excessive detail.
I have not implemented this myself, one reason being that the amount I'm able to save from year to year varies, as it probably does for you, and so predicting a path is not quite so simple as he assumes. You could still do it I suppose.
I think you could get a very crude approximation to this by simply directing your savings into cash when the share market's rate of growth over the last several years is above what you think is the long term average.