"To your point, how a business should market varies widely depending upon the product/service, market, resources, etc." - that is what I implied.
As I understand your questions so far:
I don't know anyone who does it by year now days, things change too fast, but someone maybe does, the longest I had to deal with is assessed every 3-4 month, which is enough to see and measure results. But I usually change things as soon as I get enough data to make a decision.
1. Get management to allocate approximate base amount of money for marketing no matter what; Example: 5% of revenue; 25% of profit; $5,000/mo, whatever.
2. Get management define how much MORE are they willing to invest in marketing based on increase in marketing results, i.e. faster growth, not necessarily cheaper.
3. Measure everything. If you can't measure then most likely don't do it.
4. Find Customer-Acquisition-Cost (CAC) per channel and associated volume. Know your customer's Life-Time-Value (LTV). Figure out what to go for, more additional customers at higher CAC or less customers at lower CAC.
1. Brain - to learn what works for your business/product
2. Eyes - to read about new/old ideas
3. Ears & Mouth - talk to customers
4. Tracking tools and scripts to track customer segments by their motivation, needs, source, cost, ext. - use all tracking tools, top sites use 3-4 different products in addition to in-house, each provides a bit different insight.
5. Spreadsheet to do basic calculations to compare marketing results.
If that is not what you were looking for then, please: Give me examples of processes and tools that you have in mind so I could understand what you mean.