presta
Guru
I re-use my SRAM links until the chain's worn out, I must have been doing that for years before I discovered they're not supposed to be re-usable. The spare links I carry in the toolkit are only the old ones off worn out chains.
If you just pull without squeezing the sides it will tend to round off the bits that help to stop them coming apart.Foot on the pedal and a handful of brake will close the link just as effectively.
I use a bent wire hook to pull a loop of slack chain, then it's easy to do them by hand once you're not fighting the chain tension.There are all kinds of tricks for them if you have an aversion to purpose made tools. Some of them even work.