The ideal nutrient ratios for your plants depend on what plants you grow. Many indicas, for example, create much leafier buds than the average sativa and therefore require more Nitrogen during flowering. Any suggestions you get are just where to start from. Steadily increase fertilizer levels, watching the lowest and oldest leaves for signs of nutrient burn. Every plant should finish flowering with at least the first single-bladed leaves burnt to a crisp. If they finish flowering with no damage to those leaves, you could have given her more fertilizer and could have had larger buds, assuming adequate light.
Nitrogen is mainly used for growing leaves and vegetation. Potassium is the primary nutrient for flower production. Wherever you start your fertilizer regimen from, you generally want more Nitrogen during veg and more Potassium during flowering. For example, a ratio close to 3-2-2 could work well for veg, while 2-2-3 would be better for flowering. You then watch your plants and note any deficiencies, adjusting your fertilizer mix to compensate.
You'll also want to keep an eye on certain micronutrients. Calcium and Magnesium are the most important of these, while Sulfur, Iron and Zinc are also necessary. Many organic fertilizers naturally have the correct levels of micros, which is one of their best qualities.
