Wait, but the user wants a formula, so maybe present it in a structured way. Like a 5-step daily formula or something. Let's see.

First, I need to consider the user's needs. They might be a student or someone looking to improve their English, especially if they don't have much money to spend on books or classes. The key here is providing a simple, effective formula that can be applied daily without any cost.

But I need to make sure the steps are doable and free. Maybe the formula is: Read a passage, write a summary, practice grammar, learn new words, and speak aloud. Each part can use free resources.

Need to make sure the language is clear and simple, since the target audience might have limited English skills. Avoid jargon. Use bullet points or sections for clarity.

Okay, putting it all together: Start with an introduction about the importance of learning English. Then present the formula as a step-by-step process. Provide practical tips for each step using free resources. Include a sample study plan and resources. End with a conclusion encouraging consistent use of the formula.