Supplementation with lipid-based nutrient supplements (LiNS) is promoted as an approach to prevent child undernutrition and growth faltering. Previous LiNS studies have not tested the effects of improving the underlying diet prior to providing LiNS. Formative research was conducted in rural Zimbabwe to develop feeding messages to improve complementary feeding with and without LiNS. Two rounds of Trials of Improved Practices were conducted with mothers of infants aged 6–12 months to assess the feasibility of improving infant diets using (1) only locally available resources and (2) locally available resources plus 20 g of LiNS as Nutributter®/day. Common feeding problems were poor dietary diversity and low energy density. Popular improved practices were to process locally available foods so that infants could swallow them and add processed local foods to enrich porridges. Consumption of beans, fruits, green leafy vegetables, and peanut/seed butters increased after counselling (P < 0.05). Intakes of energy, protein, vitamin A, folate, calcium, iron and zinc from complementary foods increased significantly after counselling with or without the provision of Nutributter (P < 0.05). Intakes of fat, folate, iron, and zinc increased only (fat) or more so (folate, iron, and zinc) with the provision of Nutributter (P < 0.05). While provision of LiNS was crucial to ensure adequate intakes of iron and zinc, educational messages that were barrier-specific and delivered directly to mothers were crucial to improving the underlying diet.