The entire krias shema should be read bearing in mind your willingness to forfeit your life al kiddush Hashem. This will help you fulfill reading the Shema with fear and trembling. (ShA 1 – MB 1,3)
You need to think about how each of the Ten Commandments are hinted to in the krias shema so that you don’t come to transgress any one of them. (see MB2)
Read the Shema each time as if you have received this edict from the King of kings for the first time in your life. Rather than reading it in a hurry and mixing words, read the Shema deliberately word for word, pausing between topics. (ShA 2 – MB 4)
Krias shema contains 245 words. In order to complete 248 words corresponding to the 248 limbs of man, the chazzan repeats out loud “Hashem Elokaychem emmes” and the congregation that is listening, is yotzay with those 3 extra words. (ShA 3)
The individual also adds “emmes” to the end of his krias shema. When he proceeds with the next beracha he should not repeat “emmes”, rather begin with “v’yatziv v’nachon…” The custom concerning the chazzan’s private krias shema is to add “emmes” to his krias shema as well, even though he will be repeating “Hashem Elokaychem emmes”. (MB 7,8)
When daavening without a tzibbur – at Shacharis have in mind the 15 vuvs after the Shema whose gematria totals 90 which is also the gematria of Hashem’s name three times. That will supplement the three missing words. At Maariv, have in mind the three letters of “אמת” in place of the three missing words. (ShA 3 – MB 12)
Alternatively, when daavening without a minyan, say the three words “Aeil Melech ne’eman” before Shema – that will make a total of 248 words. (Rama 3)
The custom is to recite the first possuk loudly in order to arouse your concentration. (ShA 4)
The custom is to place your right hand over your face while reading the first possuk so you won’t look at anything that will disturb your concentration. (ShA 5 – MB 17)
Enunciate the daled of “echod” clearly but not to the extent that it sounds like there is a vowel after it. (ShA 7 – MB 21)
If you said “Shema Yisroel…” without kavana and there are other people around you, repeat the possuk quietly so they can’t hear you – because you are not allowed to say it twice out loud, it seems as if there are two authorities. (ShA9 – MB22)
Reciting the Shema just before you sleep will protect you. You may repeat the first paragraph again and again including the first possuk. Some poskim say to skip the first possuk when repeating the parsha. (ShA 10 – MB 25)
It is a proper custom to say “Hashem Hu HoElokim” seven times at the Ne’ilah prayer. (ShA 12)
Upon responding to two coinciding berachos, it is preferable to say “omayn v‘omayn” rather than “omayn omayn”. (Rama 12 – MB 28)
After saying “Shema Yisroel…” say “Boruch shaym kavod…” quietly. (ShA 13)
Pause after “Shema Yisroel” before saying “Hashem Elokaynu”, and pause again before saying “Hashem Echod”. (Rama 14)
Pause before and after the sentence “Boruch shaym kavod…” (ShA 14, Rama 14)
Pause between “hayom” and “al levovecha”. Also between “hayom” and “l’ahava” (ShA 15)
Pause to enunciate the ע of נִשְבַּעbefore saying “…Hashem la’avosaychem…” (ShA 16)
Enunciate the ז of תִּזְכְּרוּ and of וּזְכַרְתֶּם. (ShA 17)
For the entire krias shema see to it to deliberately read every word seperately, so as not to swallow or swap letters. (MB 32)
Pause between “v’chara” and “af” enough to enunciate all the letters of both words. So too: between “b’chul” and “l’vovcha”, between “al” and “l’vavchem”, between “b’chul” and “l’vavchem”, between “aysev” and “b’sodcho”, between “va’avadatem” and “mehayro”, between “hakenaf” and “pesil”, between “eschem” and “mayeretz”, between “v’limadtem” and “osom”, between “ukshartem” and “osom”, between “v’samtem” and “ess”, between “oor’issem” and “oso”, between “oozchartem” and “ess”, and between “va’assissem” and “ess” (ShA 19,20,21 – MB 33 see MB 34 for more examples)
Careful pronunciation applies as well to Pesukay D’zimra, Tefilla, and to reading any parts of Tanach. (ShA 22)
Be particular not to swap a raffa letter and a chazak letter – and not to switch a shva na with a shva nach and visa versa. (ShA 23)
It is best to read krias shema with the trop. Even if you don’t, at least be sure to pause at the appropriate places so as to make the phrases understandable. (ShA 24 – MB37)
Upon reciting “ukshartom l’os al yodecha” feel your tefillin shel yad. And when reciting “v’hoyu l’totafos…” feel you tefillin shel rosh. (ShA 25)
The first possuk should be called out loud. (Rama 26)