From a personal point of view, anything we do with regard to the Blessed Sacrament is not reverent enough. Given the belief that there is the real substance of our Lord in that host, kneeling does not go anywhere near far enough, we should prostrate ourselves in such a presence. Given the need for unity in the liturgy, kneeling is the most appropriate, whilst still widely usable, posture to adopt, but there are times in mass or during adoration when I feel that kneeling doesn't come close to the reverence I believe is due.
There are three areas I would like to address in turn; firstly being in a church or chapel with a tabernacle, secondly the exposed Blessed Sacrament at mass or adoration, and finally in the context of recieving holy communion:
A church is a very special place of course, particularly during holy mass, but it is the tabernacle that makes even an empty church an extraordinary place; there is a Real Presence of our Lord in that place, all of the time (with the pedantic exception of the latter part of Holy Week). Most people have an idea of 'how' to behave in a church, but it seems that many do not know 'why' they should behave that way. A genuflection as you enter a pew - many people do this as a matter of course in any church, tabernacle or not; this seems to suggest a misunderstanding of 'why' they are genuflecting - are they genuflecting to the altar? or the crucifix? I suspect if one asked the question many people would say it was as much out of habit as out of reverence. Similar statements could be made for being silent in a church out of reverence - reverence for what? To finish this idea with a quick example; it is often said as pupils enter the school hall for mass that 'this is our church' for the afternoon, with the term 'church' being the thing that demands reverence. Discounting the fact that a hall is most definately not a church, there is a clear indication in that statement that we are reverent in a church because we are in a church, rather than because there is, thinly veiled, the Real Presence our Lord in the Blessed Sacrament.
Adoration is a truly beautiful part of our faith; we are given the opportunity to be close to our Lord, to pray, meditate and contemplate in the presence of the Blessed Sacrament. As mentioned, kneeling is the common posture to adopt during adoration but I will often, after a time kneeling, sit in order to be more comfortable, as I find this helps me think more deeply. The peace that comes with being in the presence of Christ in this way is incredible, and could easily be a whole post in its own right. With regards to the reverence due when the Body of Christ is exposed for adoration, the rule I learnt as a child was that one genuflected on one knee to the concealed Blessed Sacrament and on both knees when it is displayed in a monstrance. This rule is seemingly old-fashioned now; I can find no current reference to both-knee genuflection but there is nothing contradicting it either, so I still follow it and see many others doing the same. Some might say why should there be a difference in our behaviour towards the reposed Sacrament compared with the exposed. A fair question, to which I cannot give an answer beyond asking the return question - why behave differently after the consecration at mass? There is the concealed sacrament present in the church before the consecration but there is a perceptible change in a church during the Eucharistic Prayer, Communion Rite and distribution of communion (or at least there should be).
So this leads to my thoughts on actually receiving communion at mass. This itself has three parts: Firstly in queuing to receive communion my mind is focused on what I am about to do - not receive, but do; in the sense that I am about to enter into the most intimate connection with my Lord and God. It is all too common to see people talking to those in the queue next to them as they approach the sanctuary. At times I have found myself getting irritated at this and it distracts massively from trying to obtain a peaceful and open state of mind - I do my best, but if it is distracting one person it is probably distracting many. Secondly, actually receiving communion is a very simple thing to do and is over very quickly. It would be (and is) very easy to overlook the importance of the actual act of receiving in the extended prayer before and after. The significance of this cannot be overestimated, in that tiny space of time we take the real and complete substance of Christ into our bodies and by the same act express our desire for him to stay with us in spirit. There is a huge debate to be had over whether one should recieve on the tongue or in the hand and I don't want to digress too much into that here, but given my thoughts in the second paragraph it will probably come as no surprise that I prefer on the tongue. The final part of receiving communion for me is the returning to my pew and kneeling quietly considering what I have just done (again, done, not simply received). I know many people have particular prayers that they say after communion, and I always include the 'O Sacrament Most Holy...' prayer, but the contemplative prayer I experience immediately after communion is most rewarding - I have a real sense that God is with me, within me and all around me.
I should add as a final note that it is very rare that I use a personal, rather than collective pronoun in relation to God ('my Lord', as opposed to 'our Lord'), but receiving communion is to me a very personal moment; all are called to receive, and to the same end of connecting ourselves to God more closely, but we each experience the sacrament in a personal way.
Regardless of the context in which we interact with the Blessed Sacrament, the idea recurs that it would be virtually impossible to show too much reverence to the Real Presence of our Lord.