it could be the primer/moisturizer you’re using before applying. im not very good with skin types and making recommendations off of it, but i’d consider finding a primer that’s good for the type of skin you have (oily, dry, combination). i have combination skin so for me i use a elf primer, foundation on my face but not really under my eyes, then a light amount of concealer under eyes (a little goes a long way) blended. i try to avoid the foundation in places i’m concealing bc it’s less product which means less caking/separation. then take a sponge and bake it with some translucent powder. sometimes the separation is inevitable and part of the process but this is what helps me!

it’s gonna depend on what you’re going for. if you want the dress to pop out, then a nude might be formal enough without distracting from the clothing. sometimes i’ll do a more “natural” makeup look but use the color that im trying to highlight (like wearing a green shirt and doing a green eyeshadow)

let the glue get a little tacky before trying to place them! i notice when i let it dry just a bit longer the fumes aren’t as strong and they don’t burn my eyes as much. then i keep my eyes slightly open as i come from above my natural lashes to place them up, but also as close to my lash line as possible. i press down the center of the lash first, then focus on placing the corners down. i use my fingers bc i’ve had a lot of practice but they make tweezers for putting on fake lashes that helped me when i was learning! honestly watching instagram reels of people putting makeup/fake lashes on have been helpful cuz it’s usually up close shots

you can use a white mascara and let it dry then put the green over it, it might help! or find some green fake lashes lol

if you have any photos that would be much easier to help diagnose!:)