There is often talk of a misery of choice in investments. There are 2,000 unit trusts to choose from. So what filters should we consider? Unlike short-term insurance, for example, unit trusts remain a predominantly intermediated market ― though this is changing with the rise of self-help platforms such as Easy Equities.Yet this does not have the same traction yet in the direct mutual fund sales Charles Schwab has achieved in the US or Hargreaves Lansdown in the UK. Easy Equities remains primarily a platform to buy either individual shares or exchange traded funds (ETFs).So what are the filters that should be considered to find the appropriate funds in which to invest? Historically, past performance was the most popular filter. It is certainly relevant when it comes to filtering out the bad performers. The returns of consistently badly run funds often don’t improve.Yet we know now that often performance is linked to style, which can explain underperformance. Allan Gray and its sister global manager Orbis often had sustained underperformance for years at a time as their value investment approach was out of style. This was most notable during the 1997-2000 dot.com boom in highly speculative technology shares, in which Allan Gray and Orbis were not invested.I like to see some depth on the bench of a fund manager. Both in my personal capacity and when I was a trustee, I am concerned about the main risk. Who will take over if a key portfolio manager leaves? I am not too concerned, for example, by the departure of Hannes van den Berg as head of the core Ninety One balanced team. The firm has already recruited the highly experienced David Knee from M&G Investments to step into his shoes.The first consideration for investment should be the mandate. Let’s assume you are looking for a conservative balanced fund: focus on that category. In the five years before retirement an investor might still want to enjoy the benefits of a rising equity market but will need some solid shock absorbers to reduce downside risk. A good place to look at the options is the Alexforbes Retail Manager Watch.It doesn’t use a simple term such as conservative balanced. Instead, the Alexforbes actuaries have dreamt up the clunky term South African Global Low Equity Multi-Asset. There are now 35 options in this category to choose from.The largest funds have accumulated assets through their marketing skills in part, but they have also had to live up to their brand promise. There are some funds that have very few assets but would probably be on a qualitative short list.Take the quirky former Liberty and Absa fund manager Errol Shear for example. He built up a cult following among conservative investors. He has just R295m in his fund. His Stable fund is under the bizarre Otto 1890 brand, which sounds like a Viennese restaurant but used to be part of the troubled financial services group Sasfin. The way unit trusts are structured, clients’ money was always safe, but it’s understandable advisers and their clients would have been reluctant to invest into an unstable shop. Remember that unit trust investors can vote with their feet and leave with 24 hours’ notice, so if a fund doesn’t live up to its promise clients can easily leave.The big four conservative balanced funds are Allan Gray Stable (R63bn), Coronation Balanced Defensive (R36bn), Ninety One Cautious Managed (R24bn) and M&G Inflation Plus (R23bn). All of these funds have experienced teams not only when it comes to domestic assets but also international ones.Experience is an under-rated asset in the internet/AI era. But for now, advisers and investors still get comfort from marquee name asset managers, some of whom you might imagine have become part of the furniture and enjoy a measure of sheltered employment by now.Allan Gray doesn’t highlight individual fund managers in the same way Ninety One or Coronation do, but the investment team of Duncan Artus, Sean Munsie and Tim Acker has worked together for many years. And they use an equally experienced Orbis team for the foreign assets in their portfolio.Coronation has a cautious equity and balanced team that has been working together for close to 20 years under former Old Mutual Asset Managers chief investment officer Charles de Kock, who has recently handed over day-to-day responsibility to Pallavi Ambekar and Neill Young.Duane Cable and Sumesh Chetty at Ninety One, and Michael Moyle, Sandile Malinga and Leonard Kruger at M&G, are all dyed-in-the-wool fund managers, with the battle scars to prove it.• Cranston, a veteran financial journalist, is author of “The Mavericks”, a new book about South African fund management.