Making thigh high boots - The cheats way by LolaInProgress

Hmm tight legging yes, pants will distort them to the shape of the pants

Personally I like thigh highs with some rubbed inside them for sticking to bare skin, but most work either way, I just get them off eBay!

Do you mean like dip the finally product in latex or something? Thats not something I've done before I'm afraid!

I sometimes buy shoe grips off eBay and glue them on. If i don't have those I put dots of hot glue not he sole, works like a Grip. I find the traction generally fine but like, I wouldn't go running in them!

Honestly it doesn't make much difference I just use whatever i have around!

No reason why not! Let me know how you go!

Ive never tried tbh. Depends on the platform i suspect 

As someone who sews as a hobby, here's my suggestion. I don't know this Evangeline character, but I recognize the description of the boot detail you want. I'm actually planning to do a similar thing for my own boots when I cosplay Orphaner Dualscar from Homestuck (although his boots will only go up to my knees, the principle for the fold-over is the same).

Cut a piece of fabric in the correct color and width (to get the width, measure around your leg where the fold-over will start, preferably while wearing your stocking boots so you can measure right around the top of them—measure both legs, as they could be slightly different in circumference). Add a little seam allowance to the width if your fold-over will be a solid piece or if you'll need to hem it, so you'll have room to do that bit of sewing.

Next, figure out how long your fold-over needs to be—then cut your fabric to the right size. It should be that measurement plus seam allowance (enough for one side if it's a material that doesn't need hemming, like felt, and enough for two if the material does need to be hemmed, like cotton weaves). If your fold-over needs hemming, you might want to do that first so it's easier to do. (A long stocking is hell to drag around a sewing machine.)

*If you need to hem your fold-overs' open sides, do it now!

Now, gently (without moving your stocking) push the fold-over material down under the stocking's upper edge by your seam allowance amount. Leave it sticking up for now! Carefully (so you don't stab yourself) safety pin it in place; about one every inch/2.5cm, because stockings like to de-stretch when you take them off. (I say use safety pins because normal pins are very easy to lose if you knock them out taking off the stockings.)

*If you need to sew your fold-over into a solid ring of fabric, now is when you do that!

Once the fold-overs are pinned (and sewn/hemmed) and you've removed them, sew two lines of thread along the overlap of fold-over and stocking. One just next to the very edge of the stocking top, and one just a teensy bit further away. The double lines of stitching will keep it more secure. If you have room and/or you're not sure if it'll be secure enough, I might even run another line of thread along. More than three probably isn't necessary, though.

Now that the fold-overs are sewn in (but still sticking up) gently fold them down how they'll be for the cosplay. Tack them down with the teeniest stitches you can right below the top edge just to keep them folded down, in a thread color as close to the color of the fold-over material as you can get. (That's the thread color you would hopefully use for the whole process, but if nowhere else, use it here!) From there, you can add any necessary extra details (your X-thread, for example, or a lace trim if that were applicable... whatever it happens to be!).

And because you measured around your thigh, which is thicker than your calf (unless something is very strange), there should be no problem getting the fold-over that high up your leg. I, personally, would want to use some sort of invisible/flesh-toned garters for something like this; you might want to keep that in mind, because if your fold-overs are heavy, they will slid down your leg and you'll have to hike them up all the time. (A hook-and-eye set-up hidden underneath the fold-over, even attached to the seam allowance part of it, might be a good idea to attach them unobtrusively.)

I hope this helps! Let me know if you need any more explanation.

You could try coating it in latex, maybe texturing it so it looks more like leather than rubber. While i haven't tried this yet, I've heard it's an easy way to make latex clothing for cosplay.
It is messy and quite an effort though. You have to cover yourself in Vaseline before starting so the latex doesn't stick to you, then wear the item you're intending to coat, then carefully apply even coats of liquid latex being careful to not accidentally put in any imperfections(making sure each coating is completely dry before applying the next and it helps to apply something like talcum or baby powder between each coat, as well as after the final coat if you don't want that very shiny look). You have to wear the item the whole time it's drying(recommended to wait at least 30 minuets between each coat, with an hour being preferable, as well as waiting at least an hour after the final coat before you can remove the item you're coating) and you have to be careful not to move or position yourself in a way that will warp or stretch the latex in a way that will effect the final product. 

Me too, I feel like it would get really slippery and dangerous, perhaps you could use a puffy fabric glue/paint to create tread? or even not cover the bottom part that carries weight?

TBH cause stocking are so cheap i just replace the stockings xD

considering its stockings and such; no there would be no way to add laces