You use a brush or stylus or your finger to apply some type of paste. Traditionally, the paste was made with various colorful powders (e.g., vermillion) plus water. There are commercial pastes that are available, but I don’t know what they are made of. I don’t know all the ins-and-outs about makeup, but to me, the paste seems to have a similar consistency to mascara.
I’ve also seen stencils that can be used, and I’ve seen bindis that are similar to those fake tattoos that you rub on and fade a few days later.
I think it will largely be up to the woman, what traditions she’s following, and what she prefers.
Is anyone familiar with women using henna to mark the tika or bindi? I ask because I’m not, I’ve never seen it, yet they do such fantastic other designs with henna. Seems to me like henna would be a natural for a lasts-a-week bindi that won’t rub off, slide off or fall off (I’ve used stick on bindis, and the primary problem is that they eventually slide so they’re off center or tilted, which looks bad). So I wonder why henna isn’t used, or if it is used but I’ve just not noticed it.
It depends on the community. In some communities, a black bindi is only worn by widows. But I’ve seen women wear black bindis just because it matches their black sari.
I refrained from posting but here I go. The question itself is misguided since there is no such thing as a monolithic hindu woman.
Because Hinduism in India has a long history and welcomes diversity of opinion and practices - there are a multitude of them. Cultures have evolved in geography (east, west, hills, south…) and in time (cities, villages…).
In the US - if someone is picked up in City A, blindfolded and airlifted and dropped in say City B - there’s a good chance he or she would not be able to tell for a while if its a different city. The chances of this happening in India are not so great - but it changes as the country develops.
Some women in India wear the bindi (though call it by various names - and it comes in various sizes and there are a variety of reasons from habit, religion, …accessory…vanity… and it is worn and taken off by many much like American women (who do) put on makeup put it and remove it.)
In the olden times, when many women did not work and it is customary in many parts of India to shower daily (parts that dont get too cold) - Women will put it on after they shower. In parts of India that gets too cold - in the olden times, my guess will be they’ll put it on when they want to clean their face. In parts that get muggy and people sweat a lot - women who work in farms would not put it on.