Once you've decided on the categories of funds you want in your portfolio, it's time to choose specific funds. Always consider fees and charges. If you buy through a broker, you pay a load. That means a sales commission, usually up front but sometimes at the time of sale. Although investment experts often recommend no-load funds, buying load funds can make sense if you prefer to have a broker making investment recommendations.
All funds have management and expense fees.
Up to a percent and a half per year is customary. Sometimes there are exit fees that decrease over time. Next, you should look at performance. Not just from the recent past but look at five and ten year performance. The best funds hold their own against the competition, even when there's a setback in the market.