These structures of epidermal tissue system minimize water loss due to their presence or action
I. Bulliform cells    
II. Cuticle    
III. Trichomes

Bulliform cells by promoting inrolling of lamina minimize water loss in grasses. Cuticle being made of hydrophobic cutin minimize water loss and trichomes being present as outgrowths of epidermis of aerial plant parts decrease screen the light that reaches the mesophyll to minimize increase in temperature.