Modern English Runes
FIRST CONSIDERATIONS
The first step towards writing Modern English with runes is to pick a runic alphabet. The straightforward choice is Futhorc, since it was used to write Old English, and although it has not been updated in about a thousand years, it is still better adapted to handling the sounds of English than the other runic alphabets. I recommend the Ruthwell Cross inscription as a foundation, since it is the longest English runic text, and has certain features that are useful for Modern English.
Many people are tempted, for simplicity's sake, to keep the spelling conventions of the Modern English Latin alphabet when writing with runes, but this results in more of a runic cipher than full-fledged runic text. It is a bit like taking 26 Chinese characters, mapping them onto Latin letters, using them as though they are Latin letters, then claiming to be writing in Chinese script. I would argue that a full-fledged runic script must use both runes and runic spelling conventions. However, since English has undergone quite a few vowel splits and mergers, there is no neat way to predict how English runes would have evolved. I prefer instead to map Modern English sounds onto whatever runes stood for the same sound or similar sound, and to innovate when necessary.
Everyone must decide how conservatively they want to spell. For example, some Americans might want to spell "butter" with a conservative ᛏ, but others might want to use ᛞ to better reflect General American. Some Brits might want to write "beer" as ᛒᛁᚪ rather than ᛒᛁᚱ. Some might want to spell the second vowel in "photograph" conservatively as though it were an "oh" sound, others might want to spell it as an unstressed "uh" sound.
RECOMMENDATIONS
1: If you do not want to use ᚩ for /ɒ/ then it is available for /ow~əw/ and can replace ᚩᚢ. EXAMPLESᚦᛖᚷᛖᚱ᛬ᚹᛟᚾᛋ᛬ᚹᛟᛋ᛬ᚪ᛬ᛗᚫᚾ᛬ᚠᚱᛟᛗ᛬ᛈᚪᚱᚢ᛬ᚻᚢ᛬ᛞᚱᛖᛗᛈᛏ᛬ᚻᛁ᛬ᚹᛟᛋ᛬ᛁᛞᛁᛝ᛬ᚻᛁᛋ᛬ᛋᚳᚢ᛬ᚻᛁ᛬ᚹᚩᛣ᛬ᚹᛁᚦ᛬ᚪ᛬ᚠᚱᚫᚷᛏ᛬ᛁᚾ᛬ᚦᚪ᛬ᛗᛁᛞᛚ᛬ᛟᚠ᛬ᚦᚪ᛬ᚾᚫᚷᛏ᛬ᛏᚪ᛬ᚠᚫᚷᚾᛞ᛬ᚦᚫᛏ᛬ᚻᛁᛋ᛬ᛞᚱᛁᛗ᛬ᚻᚫᛞ᛬ᛣᛟᛗ᛬ᛏᚱᚢ ᚻᚹᛖᚾ᛬ᚫᛚᚠᚱᛖᛞ᛬ᚫᚢᚱ᛬ᛣᛁᛝ᛬ᛞᚱᚩᚠ᛬ᚦᛁᚷ᛬ᛞᛖᚷᚾ᛬ᚠᚱᛟᛗ᛬ᚦᛁᛋ᛬ᛚᚫᚾᛞ᛬ᚻᛁᚷ᛬ᛋᛁᚷᛞᛖᛞ᛬ᚫᚾ᛬ᚩᛣ᛬ᚹᛁᚦ᛬ᚻᛁᛋ᛬ᚩᚾ᛬ᛣᛁᛝᛚᛁᚷ᛬ᚻᚫᚾᛞ ᚹᛁ᛬ᚻᚩᛚᛞ᛬ᚦᛁᛋ᛬ᛏᚱᚢᚦ᛬ᛏᚢ᛬ᛒᛁ᛬ᛋᛖᛚᚠᛋᛟᛏᛚ᛬ᚦᚫᛏ᛬ᚪᛚ᛬ᛗᛖᚾ᛬ᚪᚱ᛬ᛒᚩᚱᚾ᛬ᛁᚠᛖᚾ |