Why not? Others do it and seem to make a profit.
The sad reality is few businesses generate real profits. The main income is usually from sales of goods and services, and then there are various rats and mice such as interest received. It's usually expenses that are the challenge. Expenses can be claimed for anything bought to sell (products, labour, etc), and also for the cost of running the business (rent, insurance, accounting, etc). If an expense contains a mixture of business and private costs, only the business portion can be claimed. If an "expense" lasts more than a year, it's classed as an asset and the "expense" is depreciation.
Other costs may not go into accounts for tax, but they should never be overlooked. The cost of funds (interest) for stock, debtors, fixed assets, etc and the return on effort (dividends reflecting the owner's risk) are often not accounted for in closely held businesses. When looking at a business as a whole these should always be born in mind. When it comes to selling a business, the new owner will build these into calculations when deciding what price to pay.
Many books and courses have been (and are being) written about these subjects. This site takes a much more limited focus. It is for business owners wanting daily to do their best, but always fighting fires. If you don't change something, dramatic improvements are unlikely.
We suggest a relatively simple (and yet not easy) approach. While working in the business, your job is also to work on the business. If you don't manage your business (as opposed to managing the various aspects of the business), it will manage your life. Your call.
To simplify this, break the business down into two major parts - external (environment) and internal leadership (vision, strategy, structure and culture) and operating (products and services, finances, systems and process, people and marketing). Given there are hundreds of individual steps in improving every aspect of your business, it's easy to get lost in the process. Having a structure and process ensures the daily running of the business doesn't take over from the more important aspects.
We use a model called a rocket. It's only a metaphor, but like a business, a rocket getting ready to launch and travelling through space (environment) has many internal components, each of which is crucial to the success of its mission.
Tasks don't have to be done in a particular sequence. That depends on you and your business. Some items will pay significant cash returns quickly. Others will return over longer times. There is no "right way" applicable to all businesses - and the process is never finished.
There is one task short enough to always be done early (for all businesses). It can then be used as a reference point for every other task - vision. If you say that's too "airy-fairy", welcome to the club - but I've seen the difference it can make. Of course, you can take shortcuts, giving a vision that feels like it came from a cereal box. But a two or three-sentence vision developed specifically for you and your business can change your trajectory. Nothing is set in stone. A vision can be modified (or even replaced as you go), but this should generally be no more often than annually.
Just because I've given the example of vision doesn't necessarily make it the top priority. It can be a great example of how parts build on each other.