3. Work out guidelines/checklists/rules
In investing, for example, this can be the minimum number of profitable years a company should have for you to invest. Or as simple as never investing in an IPO, or a minimum level of historical growth rate, specific leverage criteria etc. Rules also help distinguish between objective facts and personal preferences and values. We should try to see the world as it is, not as we want it to be (e.g. a typical mistake is a reaction like - "It doesn't make any sense, this cannot happen."). Rules, formulas and algorithms are better than human judgement not because of some superior insight they bring but because they are noiseless.
The primary reason model does better than people is that they are less noisy. They may not reflect reality perfectly, and their predictions will not be 100%, but they will still deliver better results than humans whose decisions are too noisy.
Guidelines are better than rules as they do not entirely eliminate the need for judgements. Yet guidelines reduce noise because they decompose a complex decision into several easier sub-questions.
A formula does not have to be complex to be helpful; a simple one is also good. Complex rules will often give you only the illusion of validity and, in fact, harm the quality of your judgments.
I think using more equal weights in investment portfolios will reduce the number of decisions you make and potentially improve your returns. It will force you to think about each investment and its characteristics and will not give you an escape route when you discover increased risk by saying, 'This is just a 2% position for me. I cannot lose too much'. As a compromise, you may have only two or three types of weights (e.g. 20% for core stocks where the risks are extremely low, like Berkshire Hathaway; 10% for all others and 5% for new positions to have the opportunity to increase their weight to 10% gradually and, thus, reducing timing risk).