Check how it connects
Some straps use dedicated case loops; others need an insert or separate attachment. Read the listing to find out what is included and which case styles it accepts. Check whether the connector interferes with the charging port. An attractive strap photograph does not establish a compatible or secure fit with your phone.
Match the length to the moment
A wrist loop and a crossbody strap solve different problems. Think about grocery bags, commuting or taking photographs at an event, then check the listed length and adjustability. Consider how easily you need to put the phone away. Do not assume every decorative charm is intended to carry the weight of a device.
Keep the rest simple
Read the attachment instructions before the first outing and check parts for wear as the merchant recommends. For an event, verify the venue's rules about bags and accessories as well. A strap can be one piece of a comfortable carry setup; it is not a promise against loss, damage or theft. Pick the design after those practical details are settled.