I'm not an expert by any means when it comes to knife sharpening.
I have ceramic rod sharpeners, DMT Diamond folding flat ones, in Fine/Medium/Coarse and Extra Coarse, as well as numerous oil stones and pocket sharpeners.

A couple of things I've learned is that while experts disagree about the proper angle for sharpening, they all agree keeping the angle consistent is critical.

Also, a light stroke is all you need. Depending on blade material (hardness) will determine the proper sharpener material you use. Some of the modern knife steels are so hard that while they hold an edge for a long time, they're very difficult to re-sharpen when dull if you don't have the proper tool.

Butchers like the carbon steel knifes. Easy to sharpen, but don't hold an edge as long as the more exotic steels will.

Most people have the hardest time maintaining a consistent angle using a stone/diamond sharpener. I do too. You can buy any number of sharpening systems that use mechanical means to hold a consistent angle, but most are not for pocket or field use.

I made a gadget for my diamond sharpeners. I got hold of some DELRIN stock. It's a white type plastic material they use in production molds etc.

My DMT sharpeners are approximately 1" wide. I cut the DELRIN the width of the DMT, and about 1 1/2" long, with a 45' angle on one end.
I used a small strip of Velcro to attach the DELRIN to DMT sharpener, with the flat base of DELRIN against the handle, and the angle toward the diamond surface. I made a shallow flat notch in top of DELRIN, so it won't slide under Velcro strap. The handle of folding sharpener acts as the stop.

Normally, you would lay the sharpener flat and stroke the knife at the proper angle, one side then the other.

My modification, you put the spine of the knife on a cutting board and hold the handle up toward you at a comfortable angle. The 45' angle lays on the side of knife. Starting at the the butt end, you just make a light stroke to tip, keeping the DELRIN/angle against the blade. Then switch hands and repeat on the other side. You start with a coarser stone to set the edge and then the finer ones to finish it. You could adapt this technique to any stone if you wished.

It's safe as you pushing Away from your body, but if your unsure or just a cautious person, you could wear some Kevlar filleting gloves if you wanted. A quick portable solution to keeping the proper angle using flat sharpeners. You can cut the DELRIN guide at any angle you prefer.
Edge angles are determined by what your using the tool for. Google proper edge angles and you'll find plenty of info.

For a good pocket sharpener, I recommend this one:

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For a few more bucks and suitable for kitchen/field use, I like this one:

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It will do a serviceable job on whatever knife you choose.
Again, light strokes are what you want.