Multimeters have been a major tool for me for nearly 50 years. I started building a kit Heathkit VTVM (Vacuum Tube Volt Meter) that took a big chunk of my savings to purchase in 1968 but it was mine no more borrowing form others. Today I use a digital multimeter for everything but audio measurements (audio requires a higher impedance input and a real meter movement for accuracy IMHO I use an FET voltmeter). The one piece of advice I have is to get the best test leads you can afford they make all the difference. Meter probes need to be as sharp as a hypodermic injection needles to cut thru the thin layer of oxide on pc boards and component leads to get accurate measurement and to make it easier to get an accurate measurement. The other advantage of sharp probes is the bite into the contact and don’t slip around causing shorts. Back in the day test probes were made that used steel phonograph needles as replaceable tips. Today there are some great probes, I prefer the type that have insulated telescoping tips that allow you to get into tight places with ease. If you don’t have good probes you will likely have a lot of bad measurements. For the other connection a good alligator clip connected to ground if possible since making measurement with 2 probes is clumsy and should be avoided if possible (besides if the device under test is powered up one of your hands should be in your pocket for safety). Today a decent digital multimeter is dirt cheap and everyone should have one of their own.
