I grew up in a home wherein virtually every room contained a publicly displayed Bible verse.
Commonly, the words were embossed on paper or sewn into cloth and placed in a frame on a wall or a table where everyone who entered the room could see it. As I recall, they were drawn from familiar texts such as John 3:16 or Mark 10:14 and were commonly words of grace and comfort. Such public displays of Bible verses were considered to be in direct obedience of these verses in Deuteronomy (and the parallel text of Deut 6:6-9) and they served to bring key biblical texts regularly into the consciousness of the members of the household. In other terms, all aspects of one's daily walk were to be linked to the word of God, permeating life and thought.
Such a practice is much less common today, including our own home, and that may be one small reason why the Bible is less well known today, even by good church folks. One factor leading to this reality may be that the rationale for such a public display was not always commendable. Garrison Keillor tells a story about a comparable practice in his home. And, when he first received permission to take his date in the family automobile, he discovered (upon parking) that his mother had taped Bible verses at key places throughout the car (such as behind the visor or in the purse drawer), one of which read: "The wages of sin is death"! While such an example shows that the practice can be taken to extremes (one also thinks of certain t-shirts or bumper stickers), public displays of key Bible verses may be in the best interests of fostering a biblical consciousness on the part of members of any household. It would be interesting to explore how the people of God might continue this practice today, and in such a way as not to be strident or overly obtrusive about it all.
In both Deuteronomy texts (11:18-21; 6:6-9), the words of the Lord are to be kept in one's heart (or mind; memorization may be in view) and the people are to "bind" them as a "sign on your hand," that is, give them ready attention (see Prov 3:3; 6:21; 7:3; this image has been interpreted literally in the Jewish community with reference to phylacteries, small leather boxes containing these words bound on the arm and forehead). Moreover, this word of God is to be talked about with the children at home or away (the importance of the religious education of children here and elsewhere, e.g., Deut 6:2, 20-21, is remarkable), and at all times of the day, and these words are to be displayed in prominent public places. The word "doorposts" is a specific reference to the entrance of the house (in Jewish practice, it commonly refers to small boxes placed there containing these words), but the word also carries the general sense of places of transition in life.
In other words, these words are to be constantly in view in every circumstance in life and they are to provide the focus for one's ongoing meditation (see Exod 13:8-9; Ps 1:2). In Deut 6:4-5, the words are these: "Hear (Shema'), O Israel, the LORD is our God, the LORD alone. You shall love the LORD your God with all your heart, and with all your soul, and with all your might." It is not essentially different for Deut 11:18-21, where "every commandment" is defined in 11:13 as "loving the LORD your God, and serving him with all your heart and all your soul"; in 11:22, the "entire commandment" is defined as "loving the LORD your God, walking in all his ways, and holding fast to him."
Such "love language" describes in general terms what is entailed with respect to obedience of the detailed commandments that follow in Deuteronomy 12-26. The love commandments have to do, not with a private feeling or emotion ("love" can often be reduced to this!), or with circumscribing the boundaries of life in a detailed way (even more common!), but with loving God and neighbor in both word and deed in one's everyday walk (see Lev 19:17-18). Such a practice will often mean going beyond the law (see the parable of the Good Samaritan or Jesus' healing on the Sabbath)! Loving God and neighbor are the "greatest" of all the commandments and "much more important" than any others (as Jesus claimed, Matt 22:34-40; Mark 12:28-34; Luke 10:25-28; see Rom 13:8-10).
In Deut 11:26-28, attention to the commandments in described in terms of "two ways": blessing and curse (see Deut 30:15-20; 28:1-14, 15-46). These words describe the effects of faithfulness and unfaithfulness: a life filled with blessings (spiritual and otherwise, such as longer life) or a life wherein one experiences negative consequences of various sorts (judgment). These effects are not the result of forensic divine decisions, wherein God "zaps" every disobedient person; they are natural consequences of one's actions in view of the created moral order that God has put in place from the beginning. Moreover, such effects are not inevitable, as if one has to do with a mechanical cause and effect in life. Rather, one must speak of a "loose causal weave," wherein such consequences are normal, but not necessary (see the role of "chance" in Eccles 9:11).
The faith of the people of God will lead to decision-making with respect to various issues that life presents. This is inevitably the case. The decisions of people of faith in their various walks of life will make a difference with respect to the nature of the life that they and others will experience. When the word of God is made an integral part of daily life in the way described in Deut 11:18-21, those decisions will be informed by such a reality and will prove to be beneficial to all.