Without physically visiting a dentist, it would be difficult to predict the outcome of any orthodontic (teeth straightening) treatment.
Poor planning can have disastrous results, sometimes resulting in gums receding and loose teeth.
When you visit a dentist, pre-treatment x-rays are taken as well as full assessment of the strength of the teeth, health and quality of the supporting gums.
More importantly, discuss with the patient to find out their goals. In many instances, what a dentist will want to improve and what the patient actually wants will differ.
For these reasons, I would strongly suggest visiting a dentist for braces.
Baking soda to whiten teeth or other foods etc.
Home whitening remedies do not safely and effectively whiten your teeth. Products like baking soda are mild abrasive, which will remove surface stains from your teeth, making them appear whiter, but not actually changing the colour of them. Long-term use of these can irreversibly damage your enamel.
They can also make teeth very sensitive. Some other home remedies are even worse (such as lemon juice) as they are acidic and will strip enamel from teeth.
Seeing a dentist for whitening is the only way to be sure you are not damaging your teeth.
Flossing with strange items (hair, plastic, string)
Cleaning in between your teeth daily is as important as brushing. Gums are delicate and need to be treated with care. Using items other than floss or interdental brushes can do more damage than good.
Repairing your own teeth at home – cracks, chipped teeth or even decay
Repairing your own teeth can make a simple problem very complicated to treat. There is usually a reason the tooth has cracked or chipped in the first place and this needs to be identified and treated appropriately or it may happen again.
Whilst repairing a tooth at home, you may inadvertently trap food or bacteria underfilling, causing the tooth to decay and ultimately lead to pain, infection or even tooth loss.
It is advisable to see a dentist as soon as possible, and if you are unable to see them immediately, keep the tooth as clean as possible, but do not attempt to repair it at home.