When using letter and number worksheets to teach preschoolers, interact with and guide the child through the worksheet. Do not expect them to work through a worksheet on their own. Education.com, TLSBooks.com and KidsLearningStation.com all offer multiple options for tracing worksheets.
LessonLearntJournal.com offers four useful guidelines for teaching preschoolers their letters. You can pair all of these guidelines with tracing worksheets. First, start with the most common sound for a new letter. These are typically the sound a letter makes in a short word such as "cat," "big" and "dog." Ensure that the tracing worksheets you use follow this rule.
Separate letters that are visually or auditorily similar to avoid confusion. The letter sets "b" and "d;" "b" and "p," "q" and "p," "n" and "m;" "h" and "n" look very similar to a new learner. The letter sets "f "and "v;" "t and d;" "b and d;" "b and p;" "o" and "u" may sound alike.
Teaching vowels and most commonly-used consonants first will help the child decode more words. You should teach lower case letters before upper case ones because the majority of letters used in reading and writing are in lower case.
When teaching numbers, KidsLearningStation.com recommends providing multiple section on tracing worksheets including a section for children to trace the numbers and then another section to write them on their own. A third section asking the child to count the number of objects by coloring the correct number of shapes also helps a child learn their numbers.