Template portfolios.
Every passive portfolio you read about, from Bogleheads to Harry Browne, tends to come back to the same few structures. Here is a curated list of portfolios, arranged in rising complexity, with the trade-offs and weight mix shown alongside each one.
Educational, not advisory.
Template portfolios illustrate published asset-allocation structures. They are not recommendations, and you remain responsible for choices that fit your jurisdiction, taxes, and horizon.
Pick one and let it sit a while.
A clear structure is a good place to begin a passive investing journey. Choose one you can understand, hold through different markets, and keep returning to without second-guessing it.