keeping house plants alive.
This! My green fingered mother with stunning back and front gardens and a house FULL of them despairs of me I can't even keep a cactus alive! She's even watched me watering etc and can't understand why they still die!
Dying within 3 months tops if I look after them.
3 months! Mine don't last 3 days!
Poaching eggs
This too. I've tried ALL the tricks...nope! The only thing I can do close to ok is microwave poaching which isn't real poaching
Make scones that rise too
Again, tried all the tricks and tips to no avail
Eyeliner
Yep! Can't do it so they match! One will be thick and winged the other will be thin and wingless
Dd meanwhile is like a flipping MUA! She can do all the contouring etc and do weird and wonderful things with eyeliner she can even do halloween shit! How? I never taught her
@PlanetNormal you are not the only one. I am a "wordy" person but my penmanship is shite if I write for more than 5 mins at a time. How the fuck my examiners read my exam essays I do not know! You know that scene in friends when joey writes his name on the board and he's not paying attention so it drifts down the way and then the underline goes THROUGH his name? That's my writing at the end of a 2 hour exam! After 3 it's illegible I swear fuck knows how I passed a-levels and 2 degrees the poor examiners must be experts in deciphering terrible handwriting!! I write stuff then go back to it even just a few hours later and I'm like "I don't even know what the train of thought was there AT ALL"
Re onion chopping - 3 words
Frozen diced onion!
@RosesAndHellebores 
I can't put a bin liner in a bin properly - any bin.
It just sort of "poufs" inwards and traps air. I have seen bins with bin liners that looks great and tidy and not full of air. Please can some kind person tell me how to do it? I have even worked in hotels and kitchens and I still can't do it properly.
Open bin bag fully
Hold bin bag by handles in left hand
Use right hand to "squeeze" bin bag narrow again
Thread into bin
Turn top of bin bag over the top edge of the bin, secure by slipknotting one handle into the other
Make hand into fist and push into bin bag until you reach bottom of bin gently and withdraw hand
Bin is now ready to use, the bag won't fall into the bin, stuff won't miss the bag and be in the bin but not the bag etc
Sounds long winded but honestly takes a few secs to do - you wanna know how to deal with bins? Ask someone with ocd!! 
Also when you then need to remove the bin bag simply untie the handles, loop around wrist as you do so and bin bag should usually lift out easily without spillage. I then place on top of bin or a suitable surface, tie it in what I call a twist knot (twist the top of the bag in one piece and knot it in on itself) ready to go out. That way you're not touching icky stuff!