Court marking is a measuring job
Sports courts are the least forgiving marking there is, because the dimensions are not a matter of judgement. A netball court is a specific size with specific thirds and a specific goal circle radius. A tennis court has fixed service box dimensions. Get any of it wrong and it is visible to everyone who plays on it, and on a competition court it can make the surface unusable for its purpose.
So the work is set out first and paint second, more than in any other kind of marking. Squaring the court, checking diagonals, and confirming the run-off around the playing area all happen before a line goes down.
Multi-court layouts
Most community and school courts carry more than one sport. That is sensible use of a slab, and it is also where marking gets difficult, because two or three sets of lines have to coexist without confusing players.
The usual approach is a colour hierarchy: the primary sport gets the dominant colour, usually white, and secondary sports get contrasting colours. Which sport is primary should be decided by whoever uses the court most, not by whoever is standing there on the day.
There is a practical limit. Three sports on one court is workable. Four or five starts to produce a surface nobody can read at speed, and it is often better to accept that one sport is not accommodated than to make all of them harder to play.
Surface matters
Asphalt is the common base for school and community courts. It is durable and cheap, and marking bonds well provided the surface is clean and sound. It gets hot underfoot in a Queensland summer and it oxidises over time.
Acrylic sports surfacing is a coating applied over asphalt or concrete, usually in the familiar green and blue. It gives consistent ball bounce, better grip and a much better looking court, and marking is applied as part of the system. Where a court already has acrylic surfacing, the marking paint must be compatible with it.
Concrete is used for some courts and behaves like a factory floor for adhesion purposes. Preparation matters more.
Whichever the surface, if it is cracked, ponding or delaminating, marking it is money spent on a problem you still have. Better to resurface and mark once.
Which dimensions apply
Court dimensions come from the governing body for each sport, and they differ between recreational, community and competition levels. A school netball court used for PE and a court used for association fixtures are not necessarily the same thing.
So the useful question before quoting is what the court is actually for. If competition is involved, the relevant association's specification is the reference, and it is worth confirming it in writing rather than assuming. If it is purely recreational, there is more latitude, particularly where the slab is not big enough for a full size court.
Run-off is the part most often forgotten. A court needs clear space around the playing area, and a full size court marked hard against a fence is unsafe regardless of whether the lines themselves are correct.
Timing
Courts are usually marked in school holidays or off-season, for obvious reasons. On the Sunshine Coast the other consideration is weather, since an outdoor court cannot be marked damp and cannot be rained on while curing.
Where a court is being resurfaced as well as marked, the acrylic system has its own cure requirements before marking can go on top, so the whole program needs a realistic window rather than a single day.