Fate Reforged is a large set with 60 commons, 60 uncommons, 34 rares, 10 mythic rares, 10 extra non-basic lands, and two variations of each standard basic land. Rare lands from Khans of Tarkir can also appear in packs, though they have the Khans expansion symbol and thus aren't really part of this set. This is the normal size for a small set of this era except for the unusual land slot. Foil cards are included in booster packs with advertised odds of 1 : 67 cards. The set was printed in English in the USA and Belgium.
Fate Reforged was sold in 15 card booster packs (which contain an additional ad card). Booster boxes have 36 packs.
The US printing uses sequential collation.
Packs are back-facing and have 10 commons followed by 3 uncommons, a rare, a land, and an ad card. If there is a foil card, it will appear after the rare, displacing a common. The land will either be a non-basic tap land, or a Khans of Tarkir fetch land. Basic lands do not appear in English boosters except as foils. (They do, however, apparently appear in Korean, Portuguese, Traditional Chinese, and Russion ).
|10 Commons||3 Uncommons||1 Rare||1 Land||1 Ad Card|
|9 Commons||3 Uncommons||1 Rare||1 Foil||1 Land||1 Ad Card|
The commons are printed on one sheet with each card appearing twice (and one filler). This is divided into a 66-card A run (with 33 distinct cards) and a 54-card B run (with 27 distinct cards). Each pack contains 5-6 A commons followed by 4-5 B commons.
When a foil appears in a pack, it will displace a common card. In all cases, foils displace B commons. Probably, common and rare foils appear in 5 A common packs and uncommon foils appear in 6 A common packs. Both basic and common non-basic lands appear on the common foil sheet. There are two foil rare sheets. One foil rare sheet has the 5 "siege" cards and Crux of Fate whose foil versions have a special watermark. The rest of the rares appear on the other sheet. The Khans of Tarkir fetch lands do not appear as foils.
Apparently, packs with 6 A commons appear 3/8 of the time. Given the foil rate, this gives A commons and B commons nearly the same as-fan, although there is a slight preference (less than 0.1%) for B commons. This can't quite be explained by inexactness of the foil rate, so there may be a rare unobserved outlier.
There is a single uncommon run with each card appearing 2 times.
The non-basic common lands are on a different sheet than the Khans of Tarkir fetch lands. It seems that the rate of appearance for fetch lands is 1/24. Probably, the fetch lands can only appear in 6 A common packs, and they can appear in the same pack as an uncommon foil, but not with a foil of any other rarity.
The A common run consists of 33 different cards each appearing twice. The cards are mostly white, blue, and black. The choice of first card is mostly arbitrary.
The B common run consists of 27 different cards each appearing twice. The cards are mostly red and green. The choice of first card is mostly arbitrary.
The uncommon run consists of 60 different cards each appearing twice. The choice of first card is mostly arbitrary.
The 10 common non-basic lands each appear three times in a run of 30 cards. This is perhaps repeated four times to (mostly) fill up a sheet. The choice of first card is mostly arbitrary.
Most of the marketing cards in Fate Reforged have a token or tip on the front face. In addition, there is a card that has an advertisement for Magic 2015 on the front face. (The front has an ESRB rating and the back has PEGI, so I'm not aware of any region differences.) They are printed on an 11 × 11 sheet with different items appearing different numbers of times. The choice of first card is mostly arbitrary.
|Abzan Tip Card × 4||Jeskai Tip Card × 4||Mardu Tip Card × 4|
|Sultai Tip Card × 4||Temur Tip Card × 4||Fate Reforged Tip Card × 5|
|Sarkhan Tip Card × 5||Ugin Tip Card × 5||Monk × 7|
|Warrior × 10||Magic 2015 Ad Card × 12||Manifest × 24|
|Spirit × 33|
There is a picture of the foil common sheet available.  The common sheet contains each common card, each common non-basic land, and each variation of each basic land once. The extra copies of Will of the Naga are presumed to be fillers.
There are pictures of both the foil rare sheet available.   On the first sheet, each rare card appears twice, and each mythic rare card appears once except for the siege cards and Crux of Fate which do not appear. The extra copies of Rally the Ancestors are presumed to be fillers. (Note that I wasn't able to verify this matches the observed foil rare collation pattern, as I didn't observe any boxes with two foil rares from this sheet. This is maybe expected due to the additional sheet.)
The second rare sheet contains the remaining cards each twelve times. (The foil versions of these cards all have a special watermark.) There four right-most rows on the sheet have blank fillers (not pictured here), and the extra copies of Crux of Fate are also presumed to be fillers.
 Information about languages that have basic lands in boosters is available in this Wizards article.
 The foil common sheet and the first foil rare sheet were posted in the Misprints facebook group by Frank Van Den Hanenberg.
 The second sheet was posted on reddit by ahalavais.