The most decisive starting point is the interaction between the Green 4 and the Blue 6. The Green 4 is in a corner, limiting its shapes to a 2x2, 1x4, or 4x1. If you test these, only placing it as a 2x2 square creates a perfect 1x6 vertical slot along the edge for the Blue 6. Any other placement creates an awkward shape the Blue 6 cannot fill. This opening move solves the entire rightmost column in one stroke.

Next, we turn to the Yellow 8 in the top-left. It can be a 4x2 (horizontal) or a 2x4 (vertical). This is the puzzle's important moment. If you place it as a 2x4 strip, it forces the Teal 3 (a 1x3 piece on the left edge) to sit directly below it. This combination would fill the first seven cells of the left-most column, leaving the bottom-left corner cell stranded and impossible to fill. This is an illegal move. Therefore, the Yellow 8 must be a 4x2 horizontal piece. This is a high-level deduction that comes with practice.

With the Yellow 8 placed as a 4x2, we can solve the rest of the frame. The Red 3, located on the bottom row, must be a 3x1 strip. To fill the now-vulnerable bottom-left corner cell, the Red 3 is forced to occupy the first three columns of the bottom row. This, in turn, allows the Teal 3 to neatly fit as a 1x3 strip in the space left in the first column.

With the grid's outer frame now solved, the inner pieces are heavily constrained. The Dark Green 4 has a perfect 2x2 space waiting for it in the bottom-right. The final two pieces, the Orange 2 and the Purple 6, then slot neatly into the remaining L-shaped space.