There are two groups out there when it comes to pagination style, so you’ll have to decide which group you fall into. There’s the “squared-off pages” group and the “no widows or orphans” group. Let me explain the difference.

Through the years, different generations have learned alternative definitions of the word “widow” and “orphan”.
Here’s how I learned it:
A widow, is a lonely line at the very bottom of the page. It’s when only one more line will fit at the bottom and that line is the start of a new paragraph.
An orphan, is a lonely line at the very top of the page where the paragraph ends.
(Image 1 depicts these two instances)
Now, other generations learned the opposite meanings. So for some, a widow is at the top of a page, and an orphan is at the bottom. Regardless of how you learned it, the information below is still the same. For this, we will use the words as defined above.

Squared-off pages:
To achieve squared off pages, you cannot be picky when it comes to widows and orphans. For the most part, you have to let them do their thing. But, you get a nice, clean layout with squared-off pages.
No widows or orphans:
If you absolutely cannot stand widows and orphans, you’re going to have to give up the squared-off look, and here’s why:
Image 2 shows your orphan, all alone at the top of the page. Well, you don’t want him to be alone, so here’s what you do:
In Adobe inDesign, you can easily change up your paragraphs throughout the whole book with a few clicks of a button. In paragraph styling, go to Keep Options and click “Keep Lines Together”. This will keep 2 lines at the start of every paragraph and 2 lines at the end of every paragraph together, eliminating all widows and orphans. Hit OK and they magically fix themselves.

But, now that your orphan is gone, you have uneven pages. You’ll see in Image 3, that there’s a line missing at the bottom of page 2.
[Microsoft Office has a similar option under the Paragraph menu, then the Line and Page Breaks tab.]
So which will you choose?
My personal preference has always been squared-off pages. It’s the style that is used in all of the books I’ve read, so that’s my default formatting method. However, if requested, I will format with no widows and orphans.
Side Note: There are some instances, where you’ll have a one-three word orphan that you just want pulled to the bottom of the previous page. This can be achieved in inDesign by using the tracking option. I typically find a paragraph before that orphan occurs, and change the kerning for that paragraph to -10. This should shift that paragraph up one line, allowing the orphan to move to the previous page. This is how I manually control the orphans to keep the squared-off pages.
E-BOOKS
Widows and orphans don’t really apply to e-book formatting, because every device reads the e-book differently. E-Books are free-flowing, so they adapt to the devices’ screen size, font choice, and font size. So if you see a widow/orphan on your Kindle Fire HD, someone reading that same book on an iPad might never see that widow/orphan. Therefore, there’s no need to worry about widows and orphans when it comes to e-books.