First a review of tanha. It literally means 'drought, thirst' and figuratively 'the fever of unsatisfied longing.' It is well established as the second Noble Truth [ § ] - the primary cause of dukkha. In the context of P.S. it is that point beyond which there is no turning back. Once the mind has been infected by craving it is not impossible to 'say no' but it is very difficult. There is a lot about life that is difficult. We regularly experience unpleasant feeling. It is perfectly natural, and healthy, to incline away from the unpleasant toward the pleasant. So where is the problem? It is an unreflective tension between need and greed, between wisdom and desire, between being and becoming. And what fogs our mirror is tanha.
"If this sticky, uncouth craving overcomes you in the world,
your sorrows grow like wild grass after rain." Dhammapada 335
More often than not when we are working with our bad habits, our addictions, our cravings, it is not within the actual craving where we find release. Having set up the intention, to maybe quit smoking, there is contact (sight, smell, thought) with resultant (habitual, pleasant) feeling - and craving. The pattern has been repeatedly established: contact - feeling - craving - upadana - bhava - (re)birth as a smoker. Puff puff. Heroin addiction is sometimes talked about as 'having a monkey on your back' - it wants (regular) feeding. It gets hungry - it digs in its claws. Try and shake it off - it digs in its claws. You can't run - you can't hide. You can only let it die. Wean it off to a degree but ultimately the only solution is starvation.

We can't beat craving so what we need to do - somewhere along the chain - is cut off the conditions that lead to its arising. Several possible access points have been discussed but the most workable is vedana. The preceding chain-links of our 'momentary arising' or 'unfolding experience' are quite subtle and barely within the scope of awareness but feeling is formed, or conscious enough so that we can catch it - if we try. As a practice, it is sufficient to begin with, just noticing the attraction toward pleasant feeling (want more) and the repulsion around unpleasant feeling (want less). As this ability develops it becomes increasingly possible to just 'sit' with the feeling and not go to craving. Or, we can change the conditions, redirect attention. In effect this is substitution or distraction - a valid strategy until until right view matures. This is the critical point - developing right view (insight, wisdom, knowledge, vijja) into the workings of the whole P.S. mechanism. This 'right-view' arises through wise attention; manasikara [see: nama-rupa].

So, see through the feeling from a perspective of vijja (not a-vijja) or just abide with the feeling or change the associative conditions. Either way, there is some conscious, intentional action and fuel is removed from the fire of craving. Do this often enough and the fire will go out - the monkey will die. This is the path toward realising the third Noble Truth: cessation of craving.

There is a paradox in relation to upadana. We need a certain amount of pleasure (joy, happiness, etc.) in our spiritual life for it to be sustainable - so we can eventually go beyond sensuality. We need views (devoloping 'right' views) to overcome our grasping of views. We need a framework of rules, rituals and precepts to support our practice - so that we can eventually transcend rules and rituals. We need a degree of personal stability and self-responsibility to overcome attachment to our doctrines of the self. We can have these things, and make use of them but need not grasp them. Finding the point of balance is part of the challenge we face.
"When seen & heard, people are called by this name or that,
but, after death, only the name remains to be pointed to.
Those greedy for objects of attachment do not let go sorrow, grief and avarice,
but sages, letting go of possessions, live in full security." Khuddaka IV.6

The suggestion in relation to grasping is letting go. And what do I let go of? Absolutely, completely everything - grasp at nothing.
       But, won't I just... disappear? If I hold nothing then won't I be nothing?
       Consider that, try as you might, you can't hold anything any way. Conditions change. We are all, in some respects, playing the game of life. Why not play to win? Sure, but the more we grasp at outcomes the more we will suffer. Even if the outcome arrives according to our craving it can be so wrapped up in anxiety and tension that we are often not able to fully enjoy it. Sometimes we win, sometimes not - don't attach to either gaining or losing - just move on.