Print Skyscrapers grids from 4x4 to 6x6, two or four per page, with the answers last. Clues print outside the grid in a large size so the edges stay uncluttered.
What a page looks like
A puzzle as it printsIts answer, on the last page
Printing tips
Next to each clue, jot the heights its first cell can still take: most deductions start at the edge.
Which size to print
A 4x4 is a five-minute warm-up, four to a page. The 5x5 is the daily Easy and Medium size, and the 6x6 Hard and Expert grids are best two to a page, because the candidate lists along the edges grow long.
Using the answer key
The key shows every height. Before comparing cells, stand at each clue and count the towers your own grid shows from there; a clue that sees the wrong number points straight at the line with the mistake.