Nonogram: the overlap
Place a block as far left as it can go and as far right as it can go. The cells covered in both positions are certainly filled. For a single block of length b in a line of length n, the overlap is 2b − n cells, when that is positive: a 7 in a 10-cell line fixes 4 cells, a 9 in a 15-cell line fixes 3.
With several blocks, push them all left, then all right, and compare each block with itself. Gaps count: 3 2 in a 7-cell line needs 3 + 1 + 2 = 6 cells, so there is only one cell of slack, and both blocks give overlaps.
Nonogram: edges and anchors
A filled cell touching the edge must belong to the first block, so the whole block is fixed and the next cell is a cross. A filled cell close to the edge works similarly: the first block has to reach it, so the cells between are limited.
Crosses matter as much as fills. A segment between two crosses that is shorter than the smallest remaining block must be empty.
Nonogram: passes
Go through all the rows, then all the columns, then the rows again. Each pass gives new fixed cells that become anchors for the crossing lines. Leave the busiest lines — many short blocks — until their neighbours have given them something to hold on to.
Binary: doubles and sandwiches
Two identical symbols next to each other must be bordered by the opposite symbol on both sides, or there would be three in a row. Two identical symbols with a single gap between them force the opposite symbol into the gap. These two patterns do most of the work on easy sheets.
Binary: balance
Each line holds as many of one symbol as the other. In an 8-cell line, once four dots are placed the other four cells are rings. Near the end of a line, balance also combines with the no-three rule: with two rings left to place in three empty cells, the middle one often has to be a ring.
Binary: the one way to finish a line
On hard and expert sheets, take a line with only a few empty cells and list every way to fill them that keeps the balance. Strike out the ones that create three in a row, and the ones that would make the line identical to an already finished line. If only one is left, write it in; if several remain but agree on a cell, that cell is settled.