Some devices come with a good wrist band. Take Fitbit Charge HR, for example:
|Fitbit Charge HR and what wrist band is supposed to look like|
It's comfortable and there almost no way to lose it between good buckle and additional security band (not shown that it has an additional claw inside to fix it in place).
While others are just crappy and too easy to lose:
|Samsung Gear Fit 2|
|And how to lose it|
|Just unstrap it with your backpack or something and it slips right off, you'll never notice|
|Huawei Talkband B2|
|Not as expensive but just as easy to lose|
I mentioned that Talkband B3
's band, while looking the same, is marginally better. But not much better.
What to do with it all?
Obviously, the first thing you should do is to let the manufacturer know about this fault. Especially if you already lose some device, go write an angry tweet or post and contact the manufacturer. Repeat often enough and maybe they'll stop doing it.
Before than happens, you can also secure the band with an additional security band. They are sold separately, search amazon or ebay for one for your particular wearable or something close (it should look kinda like the first picture, although that particular one was built-in). Do not think that Fitbit is absolutely better, by the way, Fitbit Alta and Fitbit Flex are so popular and crappy that security bands for them are in fact the easiest to find. It should cost you couple bucks at most which is a good investment if it helps you not to lose a gadget that costs several hundred bucks, don't you think so?
And what to do before you find one and wait for it to be mailed to you? I'd recommend using anything short and elastic, like that tiny band that comes with TalkBand's usb cable, don't rush to throw it away:
|A possible way to secure those crappy wrist bands, using an elastic band from usb cable.|
Or a rubber band for money/plastic bags. The trick is to not make it too tight, so you still can unclick the pin yet tight to enough to require more efforts for unclicking and tight enough to provide more tension if it does unclick.
You can also try to use duct tape, pieces of wire, glue, threads or ropes. Let me know in the comments if anything works out for you.