If you want to end suffering (attain Nibbana), you need to develop wisdom which comes from developing the Noble Eight Fold Path. Not by looking at some object.
By developing the Noble Eight Fold Path, you understand the Four Noble Truths.
Just by looking at some object will not bring you any Wisdom. See for yourself if that develops any understanding of the Noble Truth of Suffering? The Origin of Suffering? The Cessation or the Path leading to the cessation of suffering? Sure your mind will be concentrated but without any Wisdom (about the Four Noble Truths). Therefore, such concentration is not the Right Concentration.
In the Great Forty discourse, Buddha clearly shows what Right Concentration is with all the 7 preceding parts (starting with Right View) as their requisite condition. And what is the right view? The understanding of the Four Noble Truths.
Therefore, start with that. Buddha said in the Noble Truth of Suffering that Birth, Aging, Sickness, Death is suffering.
Focus on Birth - contemplate in terms of where one can be born in - hell, animal womb, plane of the departed, human world, divine world & brahma worlds. Contemplate suffering in each of those planes. And ask yourself this being the case, is there any place for me be born and call it a happy destination?
Then look at yourself, aging - compare to how it was when you were a child and how you have aged now. Contemplate on various sickness in the world and how the next moment you can get the same.
Then contemplate on Death. As Buddha said, contemplate on a dead body left out there for days, oozing, eaten by insects and animals, contemplate the disgusting nature of that and think such is the nature of "my" body. I have not escaped this.
Then ask yourself, what is the Origin of such a Form? How did I get this disgusting thing? Then use this below Concentration Discourse and meditate on the arising and passing away phenomena.
https://suttacentral.net/sn22.5/en/bodhi
“And what, bhikkhus, is the origin of form? What is the origin of
feeling? What is the origin of perception? What is the origin of
volitional formations? What is the origin of consciousness?
“Here, bhikkhus, one seeks delight, one welcomes, one remains holding.
And what is it that one seeks delight in, what does one welcome, to
what does one remain holding? One seeks delight in form, welcomes it,
and remains holding to it. As a consequence of this, delight arises.
Delight in form is clinging. With one’s clinging as condition,
existence comes to be; with existence as condition, birth; with birth
as condition, aging-and-death, sorrow, lamentation, pain, displeasure,
and despair come to be. Such is the origin of this whole mass of
suffering.
Take your own example and ask do I seek delight in form? Do I eat anything on the table or do I seek something I like? Do I eat and say it's tasty? Do I welcome it? Do I remain holding? Having seen a person do I say he or she is beautiful? Like this just observe by looking at your examples. Then see as a result do I cling to it? The next day also do I want the same thing? Like this contemplate all the way to Birth. This is how I got this mass of suffering.
Now you can contemplate on the passing away phenomena - what is the cessation? See if you did not seek delight in form, did not welcome it, did not remain holding, won't the delight cease? If there's no delight will there be any clinging? Like this contemplate and you see there is a cessation of this form.
Try to understand the Dependent Origination. What it means when the Buddha said "with Existence as a condition, Birth" or because of Craving, Suffering come to be.
This is how you should understand impermanence. By understanding the arising and passing away phenomena of form, feeling, perception, volitional formations and consciousness.
The commonly accepted Vipassana techniques today are all polluted with non-Buddha teachings (mainly due to Commentaries esp. Visuddhimagga and Abhidhammatta Sangaha - both works of non-attainers).
Everything that the Buddha teaches is towards the goal of Nibbana. The whole doctrine is within the Four Noble Truths.
If not for a great Dhamma Teacher I too would be in your boat. Therefore with much compassion I write these details for you to also try contemplating on Dhamma and see the results.
Full meditation I mentioned above can be found here
