I think there's two ways of looking at it Paul
1) Market heavily during traditionally slack times, to compensate and fill up the diary. This could cost hundreds more per month, and results aren't guaranteed.. .but could have better longer term effects on your bottom line.
2) Stop trying to push a rock up a hill with your nose, don't speculate too much in Jan/Feb... rather throw money at marketing at times like October/November when you can be guaranteed to pick up the pre-Xmas rush and make a mint.
I've always used the 2nd approach, but getting to the point in my business now when I need to start the other approach... having spent most of the last 2 months up to Xmas booked almost solid, I wouldn't want to up my marketing any more at that time... instead I probably need to try and crack Jan & Feb, something I've never mastered to this day.
I think commercial is the way with the first two months of the year, which I'm working on at the moment.
The thing is, no two businesses are the same... I find it unbelievable that people say they are not stacked out in December, but then I am very jealous when people say how busy they are in January.
It'll take you a few yearly cycles to really get a feel for your business's ebbs and flows. All I would suggest is you get familiar with microsoft excel, if not already (or find a nerdy friend who does, everyone has one
). Use it to build statistical views of your turnover, profit, number of enquiries/jobs and also to track the spend and success of your marketing, as well as other passive sources of business such as recommendations & repeats.
You can suddenly view your business in a whole different light with these kind of stats, but beware of making something look good when it isn't or vice versa... .after all... lies, damned lies and statistics.....