The basic shader for Unity. A template to make more advanced ones.

BareBoneShader.shader

Shader "CustomShaders/BareBoneShader"
{
	//Properties
	Properties
	{
		_Color("Main Color", Color) = (1,1,1,1)
	}

	//Subshaders
	SubShader
	{
		//A pass for this subshader
		Pass
		{
		//CG CODE SECTION
		CGPROGRAM

			//Define and register the vert and fragment functions
			#pragma vertex vert
			#pragma fragment frag

			//Variables declaration inside CG, plugged into - the properties
			uniform half4 _Color;

			//The pack sent to the vertex shader
			struct vertexInput
			{
				float4 vertex : POSITION;
			};

			//The pack resulted from the vertex shader, that will be sent to the fragment/pixel shader
			struct vertexOutput
			{
				float4 pos : SV_POSITION;
			};

			vertexOutput vert(vertexInput v)
			{
				vertexOutput o;

				o.pos = mul(UNITY_MATRIX_MVP, v.vertex);

				return o;
			}

			half4 frag(vertexOutput i) : COLOR
			{
				return _Color;	
			}

		ENDCG
		//END OF CG CODE SECTION
		}
	}
}