Whenever i build an Real Grade i always make it a habit to buy its specific waterside decals. Why? since the RG kits only come with clear or aluminum decals which shows the edge of the sticker when placed. So i like waterside decals better. but RG have metallic reflective stickers, which waterside decals don't have. 

stock decals

i will be applying the stock decals to the RG Zeta.

remove the sticker using your tweezers.

dip in water to lessen its tackiness. then apply its specific area.

press it down with a cotton swab or your fingers till the water gets squeezed out.

Wetting the decal gives you better control  while placing it and it helps blend it with the surface.