how to find a good USB cable?

This is actually a very good question, and I've found even the best connectors fail over time.

1. Select one that reduces stress on the plug. So, for example, if you're at all like me, surfing your phone or tablet at 2:37 AM with it propped up on your chest with the charging cord poking out the bottom, a straight end plug is going to stress the connector and break:

https://encrypted-tbn0.gstatic.com/shopping?q=tbn:ANd9GcT1gXe4BSpHPtwYmJsIOynt7Xl_6pNmnmsGOv-HBNEzdFlye3hZEJCGmSrkGfy43WYPNYlf6o-oTzoK4E1ijTPbwDrOpr2ots3s4dAg7Zk2_NUWW77XgTJxeA

An L shaped or right angle connector in that same scenario won't stress the cable as much and should last a lot longer:

https://i.ebayimg.com/images/g/hccAAOSw7pNi3-qB/s-l1600.jpg

2. I found having a fabric wrapped cord to be more reliable than a bare cord but that's just me.

3. When it comes to fast charging, yes, you need a capable cord, but you need a proper outlet. Having a crappy cord on a good outlet is just as bad as having a good cord on a crappy outlet. Weakest link.

USB-IF certification is a good start

Honestly, I have found IKEA (USB A to USB C in particular) cables to be the best quality ones. All of the retail "premium" or OEM cables break before a phone lifecycle, but my IKEA cable has lasted longer then 3 phones.

This is more complex than you'd think because the USB spec has changed many times over the years, with updates in the connectors used, along with other sub-category changes to cables too. So there's USB versions 1, 2, 3, and 4 (and sub-versions too), along with different types of connector, eg. USB-A comes in regular and V3 (blue inside), and USB-C which is the later. Newer specs can transfer much larger amounts of data. Power Delivery (PD) is another sub-set of specification, which currently allows up to 240W of power with USB4, that's a lot, enough to charge multiple laptops at once, vastly more then the 2.5W allowed for USB 3. For more confusion there is also USB Power Delivery Programmable Power Supply, which is a sub-set to help devices negotiate charging speeds.

Another challenge - USB-C connectors can also support Thunderbolt, which gives it a whole other set of capabilities. This depends on both the cable and the port.

This explains that mess that is USB-C: https://www.androidauthority.com/state-of-usb-c-870996/

Key part:

The latest USB data speed protocols are split into several standards. There are legacy USB 1.0 and 2.0, USB 3.0, USB 3.1, USB 3.2, and the latest USB 4.0, all of which can be supported over USB-C. Confusing enough, but these have since been revised and updated to include various sub-standards, which have encompassed USB 3.1 Gen 1, USB 3.1 Gen 2, and USB 3.2 Gen 2, along with the more recent USB 3.2 Gen 1×1, USB 3.2 Gen 1×2, and USB 3.2 Gen 2×2 revisions. Good luck deciphering the differences without a handbook. Hopefully, the graph below helps.

You'd hope USB4 fixes it, but no. USB4 already boasts Gen 2×1, Gen 2×2, Gen 3×1, Gen 3×2, and Gen 4 variations, with data speeds ranging from 10 to 80 Gbps.

Cable lengths can also have an impact. The spec only allows for a specific length after which you need active cables, which include chips in them to strengthen the signal.

Several years ago a Google engineer started buying USB-C cables from Amazon and reviewing them in a lot of detail: https://www.amazon.com/gp/profile/amzn1.account.AFLICGQRF6BRJGH2RRD4VGMB47ZA

If you read some you'll see there are plenty of manufacturers who just don't even stick by the rules, so it's not always clear what you'll actually get. It doesn't help either that some products also don't play by the rules and have custom sockets that need specific vendor cables. I've had keyboards, for example, that only work with their specific vendor cables, not general USB-C ones.

This means you need to stick to a reputable set of brands, or the cables that came with the product. Decide if you need to charge something serious with it - eg. laptop, vs just a phone, watch, or small device, or whether you need data connectivity.

As another poster mentioned, just buy Anker, they're well made come with a reputable warranty, and aren't actually that expensive. Don't buy the cables you find by the supermarket/CVS checkout, or some ultra-cheap site. They might work, they might not.

Oh, and the Google engineer had his laptop fried by bad cables: https://www.engadget.com/2016-02-03-benson-leung-chromebook-pixel-usb-type-c-test.html

StarTech.com always provides a strong, reliable cable. And offers a ton of right-angle/L-shaped connectors as the other poster mentioned.

There's a "power delivery" qualification for usb cables.

I always go with Anker cables if I'm not using the ones that come with my phone or wireless charger specifically. Having everything you buy be usb c helps a lot.

USB is just a standardized cable/connector used to connect devices together. The cable itself should not change how fast data is transferred or a battery charges when looking at different manufacturers, however using a USB 2.0 cable between USB 3.0 devices will limit any transfers to the slower 2.0 speed. Getting the "top of the line" Monster cables with gold-plating and extra shielding won't make the electricity in the cable move faster, it will only burn an extra $50 from your pocket.

If you are having trouble with getting a reliable connection, try getting a can of computer duster and a needle to see if there might be some lint or dust packed into your USB ports