This document presents 28 accepted principles for modifying instruction to better meet needs of handicapped and at risk students. The principles include, among others: get to know the individual student in an informal manner; examine the patterns of children's errors; sequence skills to reduce error rates; vary response, testing, and grading options; include study skills in the curriculum; use structured presentation tactics; supplement classroom management plans with specific prevention-oriented techniques; go beyond standardized tests; relate written symbolism to what children already know; ensure overlearning of basic skills; and utilize parents as an instructional resource. Eight models for adapting and modifying curricula are also presented. Main model characteristics and originators are: a five-step process (John Hoover); a 3x3 table to organize adaptation (S. B. Cohen); interactive units (John Cawley); focus on three basic topics (R. A. Lambie); provision of an underlying organizational framework (C. O. Cheney); TTMME (Task, Time, Method, Material, Evaluation) by J. Scourfield, secondary school considerations (Colleen Blankenship); and modification of materials for mainstreamed students (J. Burnette). A checklist to help teachers prioritize the instructional principles is appended. Includes 57 references. (DB)