Hello MaryJane,
Two things here to consider.
(1) regarding others, and (2) ragarding myself.
The one regarding others have to do with the nature of men. We may say that we are today more civilized or evolved in many ways that what used to be imodest now falls under the category of modest. But when it comes to judging wether something is modest or not it has to be measured by its effect on men. Men are men. They are the same two thousand years ago and today. That means that what used to make them lust two thousand years ago is the same that makes them lust today. This part of the human or man nature has not been civilized or evolved.
Regenerate and unregenerate men are equally effected by visual lust, and it stays with them for along time, sometimes they have to battle the visual images in their mind for years.
To my shame I know that I have been the cause of lust to men before I knew these things. That is why it is very important to educate women about these things.
So, as a rule, a godly woman who knows that her body belongs to the Lord will do everything in her power to avoid stirring lust in men. It is a good thing to ask your husband or father for his opinion on wehter your dress is provocative, because for most women visual lust is not a problem at all it is easy for us to wear the wrong thing thinking that it is modest when it is not.
Also because as even saved men struggle with visual lust, also saved women struggle with competition and jelousy, so it is easy for us to copy a woman who looks pretty even if she is dressed imodestly.
As for a rule, anything that is revealing or cleaving will stir lust in men and should be avoided.
(2) Regarding myself. I have found that our minds as humans can not be crowded with the heavely and the earthly at the same time. One will have to choke out the other.
If I am spending too much time to get my hair done and getting dressed, If I am too occupied by how I look, that will in turn choke and slow down my inner sanctification.
What we do with our time has a tremendous effect on our inner life. And that goes for anything not just dress.
I have found that the beggest snare for women in churches is their competition of who should be the Proverb 31 woman.
The house of God has become a place for recipe exchange, and quilting projects, baby and bridal showers when it is supposed to be the house of prayer. I have nothing against proverb 31 woman. She was a godly woman that is to be followed. But her inner life is what attracts me most. Her mouth speaks wisdom and she stretches her hand to the poor. But these are the areas that are most often neglested about her character. In our strive to counter oppese the feminists and be home wives we can also be ensnared in another form of wolrdliness. but that is another topic. The lesson we must learn here is inner godliness that will necessarily produce external godliness.
I do not wear makeup now nor do hair dos, so I can't say anything there, but remember, if it crowds the mind or consumes the time, it is to be avoided. The Lord wants our whole mind, heart, soul, strength and if I may add, BODY for himself because it is where He has His abode.