Two common things are apparent in many businesses.
1. When times are good marketing is last on the list.
2. When times are tough, marketing seems a great idea but finances and will are low.
To better deal with these situations a marketing plan can help in removing these recurring issues.
Better still a comprehensive business plan revised every year would do wonders.
Whilst not a silver bullet, committing to a regular marketing plan and aiming for a specific direction for your marketing will assist in eliminating the above issues
A good read is about the SOSTAC model of marketing in its step by step form see what you think let me know.