The track has holes every eight inches. Your studs are every sixteen. Those two numbers decide your afternoon.

Ask them not to pre-cut the top track

This is the most useful thing on the page and almost nobody knows to ask. Elfa systems are supplied cut to your closet dimensions, which sounds like a service and creates the problem above: with holes every eight inches and studs every sixteen, a pre-cut track either lands on studs at alternate holes or misses them completely, depending purely on where the cut fell. An owner who fought this concluded they would request an uncut track next time so they could cut it themselves and make the holes line up with their own studs, noting that this is exactly what the paid installers do. The track cuts with a hacksaw. Ten minutes of cutting beats two hours of improvising.

Do not accept a track held only by drywall anchors

The entire weight of the closet hangs from this one component, so the anchor matters more here than on almost anything else in the home. Elfa supply drywall anchors and they work, but a track with no screws into structure at all is doing everything on anchors, and the owner report above describes drilling extra holes through the steel track specifically to reach studs, while being clear that this was their own solution rather than a Container Store recommendation. The better answer is to arrange the track so it can reach studs in the first place, which is what an uncut track lets you do.

Match the anchor to what is actually behind the drywall

Elfa’s guides cover several wall conditions and they are not interchangeable. Where there is no stud, enlarge the hole to three eighths of an inch and fit the supplied anchors, tapping them in with a plastic mallet, and tighten the colored anchors until the screw stops turning. For drywall over sheet metal studs, drill an eighth inch hole the length of the sheet metal screw. For masonry, use the masonry screws and specifically do not overtighten, since that strips them. And where a masonry wall has one by two furring strips behind the drywall, put the top track into the furring strips wherever you can.

Square the solution before you load it

Elfa gives a specific sequence and it is worth following. Hang the standards on the track, push them together, add all the brackets, position the standards according to your space plan, then add the top shelves to hold them in place. Doing it in that order squares everything up while the parts can still move. It is also why standards are not screwed to the wall, and they should sit at least half an inch in from the ends of the track.

Brackets cannot go at an extension joint

For taller closets, standards are lengthened using an extension standard joined with an adapter. The constraint to know at planning stage is that brackets cannot be installed at the connection between the two. That is a real limit on where a shelf can sit, and it is much easier to design around on the plan than to discover when the one shelf you wanted at that height will not mount.

Run the lighting cable before the shelves go on

If lighting is part of the design, the cable runs down inside the hanging standards using cable organizers, with the connector ends pulled through the correct slots and left hanging three to four inches proud at the bottom. That is straightforward while the standards are empty and awkward afterward. Fold the connector ends back so they cannot drop back through the slots, which is the small trick their guide calls out.

There is a freestanding option if the wall will not cooperate

Worth knowing before you compromise on an anchor. Elfa also make freestanding uprights that stand on feet with adjustable levelers, for situations where you cannot or would rather not fix into the wall, such as a rental or a wall you do not trust. It is a genuine alternative rather than a lesser one, and it is better than hanging a loaded system off anchors in a wall you have doubts about.