Poll

The first book is often the best and then it goes downhill or too convoluted.

Yet, the first may also be just getting feet wet and the next is passed on what went right in the first book as in the Dune series.

Some series just become monotonous. So, where you start is what you think of the series as Zane Gray.

Then there is the series in which the author has the audacity to die. If you are lucky, he left a daughter that can carry on the series, as in Tony Hillerman.

I am starting to like comments in Cat in the Stacks Mysteries by Miranda James.

Generally I try to read series in order, whenever possible, but with some long running series finding the older books isn't easy. As long as the authors try to make their books work as stand-alone works, it can work... but nah, in general I try to read them in order even if it means scouring libraries across multiple counties and used book stores.

When I was little I used to go to the library all the time and pick books that looked interesting (usually an animal on the cover 😂) and nine times out of ten I would realize later that it was in the middle of a series. I honestly don't know why it never occurred to me to seek out the first book in the series but I didn't have a computer so I didn't know about library catalogues or holds so it wasn't like I could find out if they had the book.
Basically I took whatever books were available in the series and didn't worry about it.

Usually not because it's better to know everything in order... exceptions being say a series of mystery novels where each case is so separated that the books stand alone well enough.

I have done this many times, only to find new authors and characters that I must follow. Sometimes, going back to the beginning of the series to get more background.