Ok. From the top down.
If you've got hair that's not agreeable to wind or humidity, find an updo that suits both your personality and your clothes. If you wear several vastly different styles of clothes eg a suit to the office and a tracksuit on weekends, you're most probably going to need to master two updo's. Check the weather forecast on waking and if the weather is unfavorable style your hair in the updo. Another note regards hair. If it needs washing daily so you can effectively restyle it, accept this and have it at a length/haircut that doesn't annoy you to do it. Cut off your split ends and if you're having to do that more than a few times a year - use more or better conditioner. Experiment until you find effective styling products including experimenting with the amount needed. They don't need to be expensive. Always carry a clip/hairband/hairbrush or whatever else you need to restyle quickly in an emergency, then no matter what, you avoid looking like a total tramp.
If your makeup slides off...
a) try mattifying skincare as your base.
b) If your skin feels at all tight, it needs moisturising, whatever you're currently using isn't enough. Makeup won't sit well on dehydrated skin.
c) Less is more especially if you don't have makeup skills, as such. Don't try to transform yourself just aim to look like you, but a smidge better.
d) Shape your eyebrows, removing stragglers weekly, a teeny tiny bit of vaseline and brush into place will keep them tidy.
e) Carry powder and use it if you get too shiney, check at least once (lunchtime) and preferably before leaving work too. Carry eyeshadow and reapply if necessary. Carry lip balm, you can use a smear of it it on dry patches, eyebrows, eyelashes too to re-gloss yourself if necessary.
f) If you don't wear makeup at least carry tissues, take one opened out and put it on your face, smooth your face (not wipe it) with the tissue on, it'll absorb excess oil. Works if you're wearing makeup too although a little will come off on the tissue.
g) if you're too red, use a green colour corrector as primer or powder.
Nobody cares if you have wrinkles or peach fluff on your face. But deal with your beard whiskers even if it means going to a salon. Wear sunscreen, skin cancer isn't a good look. Nobody cares if you have body hair (as long as it's not poking through your tights, looking at you Ms History Teacher (mine, not all history teachers!)) but don't have halitosis or BO, find a solution.
If you lose earrings, get the ones with hooks like a U shape that go through your ear and dangle down or the circle ones where the bit that goes through your ear kind of hooks into the other bit. They don't come off so easily as the ones with butterfly backs.
Watch your posture. A lot of looking like a sack of spuds is slumping. Stand in front of a mirror, are you even or slouched to one side? Get treatment if needed and be aware of your posture, correct yourself regularly, it gets to be a habit after a while.
I know you're tired, rushed, stressed, anxious etc but pause for a second and pick your face up. Literally use your face muscles, raise your eyebrows and corners of your mouth like half a cm or something. Look in a mirror and do it so you can see what I mean. You instantly look better and less downtrodden, especially combined with posture. Also smile. Nobody actually has to have resting bitch face, your face can look however you want it to but you have to use your muscles to achieve it, nobody is going to do it for you!
Find the smile that works. Practice in the mirror. If someone points a camera at you, put it on your face. No more pics of you grinning like a psycho, or with a double chin even though you're only size 10.
If you wear glasses get a style and colour that matches your clothes as well as your face.
Wear clothes that fit.
a) If they're rolling up or falling off they don't fit. Maybe you need different fastenings, different necklines, different waistband, different size, different brand or store, different way of doing buttons eg I do middle 3 buttons on a fitted cardigan, other methods and styles of cardigan make me look like a tramp. See also: posture.
b) Experiment, find something that works and stick with it. Fashion comes and goes but if clothes don't suit you, don't hang right etc you're going to look like a bag lady. You are the centre of your life (maybe second after DC). If you can't be bothered to find clothes that fit, there's nothing I can say that will help, except work on your self esteem.
c) If you're not good at matching clothes, forget trying to! Find some outfits that work and wear them on rotation. It's not compulsory to mix and match your clothes, especially if the end result is looking like you got dressed in the dark.
d) Iron clothes that need it, nothing should look crumpled before you put it on, it makes a massive difference.
e) Have an awesome coat that makes you feel a million dollars and suits the style of your clothes as well as your skin tone.
f) If you don't know what your colours are, put them near your face and look in the mirror. If you resemble a corpse that colour isn't for you, if it perks up your skin tone and brightens you then buy it. Your skin tone changes as you age so revisit colours occasionally.
Have your nails painted/unpainted, long or short, but file them so they're neat and carry a nail file for when one snaps or splits.
Regards carrying this and that. You're going to need a bag. One that matches your style. If yours comes from Tesco (other brands of carrier are available) then you may as well accessories with a dog on a string and a twig in your hair. Just don't. If you've got a bag bag and a Tesco bag for the overflow, buy a bigger bag.
Stop rushing, that'll deal with the harried, panicked, wild eyed, out of breath look and sometimes the sweating too. You can sweat from anxiety, so leave "emergency room" in your schedule to avoid being late. If you can't do this, look at how much you're taking on - it's probably too much. Life is for living not for rushing through quickly, there's no pot of gold at the finish line, just a coffin.
Signed: that gawky unfashionable fugly teenager who dressed like a bag lady, but finally figured it out.