I have no idea how to dress when it's between like 40 and 70 degrees. NO CLUE. Jacket? Shirt? Cardigan? Sweater? I'm always too hot or too cold or really just uncomfortable with how I look.
Ah, this is a toughie! Especially when it starts getting to those days when its warm during the day super chilly once the sun goes down. The trick is layering. I mean, I know you already know this and probably do this but sometimes it can take a while to hit on the exact amount of layers appropriate for the whole day.
40 - 50 degrees
At 40 it's still kinda chilly but you're probably tired of winter already and don't mind being a little cold if it means you can leave your bulky winter coat at home. I have a short corduroy jacket that I've been layering over a light wool blazer, it's warm enough that I can wear just wear a long-sleeve shirt under it and still be comfortable.
By now I'm really tired of wearing tights under my jeans, but sometimes that's really what I have to do. To make up for it, I switched them for footless tights. You'd be a surprised at how liberated a little exposed ankle can make you feel!
50 - 60 degrees
This is kind of ideal temperature for the cutest layering options because at this point you can let go of all extraneous layers and just wear things that look good together. A sweater and a light jacket [a jacket I owned ] might be all you need and you can really bring out your cute tights and socks combo if skirts are more your thing.
This is a good time to say goodbye to tights under jeans. You might get a little cold if you're out at night, but if you're out at night you'll probz be drinking and you won't feel a thing anyway.
60 - 70 degrees
Rejoice! This is basically spring weather. Legs can be bare and knee socks can come back into your life rotation. All you need is a light jacket, maybe a cardigan! It all depends on your cold threshold.
Thin layers: Think about things that you can easily take off/on as the temperature changes. Thin layers really let you control your body temperature and won't take a lot of space in your bag if you're on the go.
Accessories: A scarf and hat go a long way. They don't even have to be super warm and wooly, but a scarf especially really makes a difference even if you're just wearing a little jacket. These are the last two items to leave my bag during the winter-spring transition period.
Deal with it: You will probably be a little cold somewhere along the line. That's just the price to pay when you've told your winter clothes to go screw themselves and you're wearing spring stuff whether the weather decides to cooperate or not. I do this every year. Someone's gotta teach mother nature a lesson!