3 ideas
Start a new idea as a small position and add to it only as further research, company meetings and price action confirm the thesis, so a holding's weight reflects accumulated conviction rather than first enthusiasm. Size each holding relative to its index weight, and let the largest bets grow out of theses that keep surviving scrutiny.
Keep re-testing every holding against the original investment case, asking whether you would buy it today at this price. Sell when the thesis has changed, when the valuation target has been reached, or when a better idea needs the capital. A falling price is a prompt to re-examine the case, not by itself a reason to sell.
Treat meetings with management as a way to detect inflection points and judge people, not to collect guidance. Use open questions, ask management about competitors and industry dynamics, and notice what they avoid saying. Repeated meetings over time reveal shifts in tone and strategy that the published numbers show only later.