I was once advised, along the lines of:
Wear niqab when you want to wear it the most, because you will never feel that way again. Even if you wear it later in your life, that same feeling – it won’t be there.
Regardless of whether or not this is entirely accurate (though I personally feel it is), the message remains, which is that you rush to do good, before you are unable to do it. If your heart is inclined towards good, you thank Allah swt for it, and you act on it. Or in other words, you thank Allah swt for it by acting on it.
“Allah says: ‘O family of Dawud, do thanks.’ As if ‘thanks’ is an action. Do the action of thanks. So you show gratefulness to Allah by using the blessing in the service of the Blessor, the One that gave them to you.” — Mohammad Elshinawy Abu Abbaad in A Test Called Life
You know the trials will come but you trust that Allah swt will provide for you ways out of your upcoming difficulties, from sources you could have never have imagined. It may be that a parent is against you wearing niqab, and then Allah swt shows you He is Capable over All things, by making that same parent, the one who becomes your support as you wear niqab. Impossible? Don’t doubt the power of Allah, the Mighty and Majestic.
“… And whosoever fears Allah and keeps his duty to Him, He will make a way for him to get out (from every difficulty). And He will provide him from (sources) he never could imagine. And whosoever puts his trust in Allah, then He will suffice him. Verily, Allah will accomplish his purpose. Indeed Allah has set a measure for all things.“ Surah Talaq, 65:2-3
I was also advised, along the lines of:
Sometimes you just have to put it [the niqab] on, and walk out of the house, because the more you wait and sit around, the more chances you are giving shaytan to waswas (whisper) in your ear.
waAllahu ta’alaa A3lam