Read a crochet pattern twice before buying all the yarn: once for the finished project, and once for the instructions you will actually follow. A photograph can show an appealing object without revealing whether it is worked in rows, assembled from motifs or shaped as you go.
Start with the notes, not row one
Find the terminology convention, finished dimensions, gauge, materials and abbreviations. Check whether a turning chain counts as a stitch and whether the project is turned between rows or rounds. These are instructions for that particular design; do not borrow the convention from your previous project.
Mark the size you intend to make if several sets of numbers appear together. For example, in a hypothetical instruction containing counts of 24 (30, 36), select the count corresponding to your chosen size in the designer's size key. Keep that selection consistent through the whole pattern.
Expand one repeat on paper
Asterisks, brackets and parentheses often group repeated instructions, but the pattern's own explanation determines their scope. Identify what happens before the repeated section, what belongs inside it and what happens after it. A plain-language rewrite is useful when you keep losing your place.
Imagine a row of 12 stitches with this instruction: repeat “1 sc in next stitch, 2 sc in next stitch” six times. Each repeat uses two existing stitches and creates three new ones. Six repeats therefore use 12 stitches and produce 18. This is a counting example, not a complete project pattern.
The distinction between stitches consumed and stitches created explains increases and decreases. If your total is wrong, compare both sides of the repeat before assuming the printed count is a mistake. Chain spaces, skipped stitches and grouped stitches need their own accounting.
Use the end-of-row count as a checkpoint
Count before beginning the next row, especially during a new repeat or a shaping section. If the target is 18 and you have 17, finding the missing stitch now avoids carrying the error into later instructions. Mark the start of a repeat if the pattern is visually difficult to follow.
Write down which row you have completed, not simply the last row number you looked at. “Row 8 finished; next is row 9” is an unambiguous restart note. For multiple sizes, include the chosen size beside that note.
Know when a calculator helps
The stitch calculator can estimate a rectangular stitch count and align it with a repeat. It cannot interpret a whole pattern, place shaping or decide how many setup chains the designer requires. Use the terminology converter when a known US or UK term needs translating, after confirming the convention.
If a step remains ambiguous, check the designer's corrections or contact the pattern source with the row and the point of confusion. Do not rewrite a fitted or shaped pattern solely to make one line's arithmetic convenient.
Reference: Craft Yarn Council: reading crochet patterns. The numerical exercise and reading checklist above are original examples.