There are multiple ways that investors can try to make an excellent passive income. Buying property and putting money into savings accounts are two traditionally popular methods. Peer-to-peer lending is also growing rapidly among those seeking a second income. I think building a portfolio of UK shares is the best way to create a supplementary income stream, however. This method doesn’t require huge upfront costs like property investment. I am also likely to make a better return than I would from a simple savings account. History is not always a reliable guide of what to expect. But with the right strategy, I could make an average annual return of up to 9.3% by buying British stocks. This in turn could provide me with a healthy passive income for retirement. If things go to plan, a £9,000 lump sum investment in UK stocks today could eventually provide a £1,220 monthly passive income. Here’s how I’d aim to achieve this. My initial step would be to open a tax-efficient financial product to hold my shares. In the UK, we are talking about either an Individual Savings Account (ISA) or a Self-Invested Personal Pension (SIPP). The £20,000 annual allowance on an ISA is...