DFA for binary language with constraints on triplets
Imagine writing a program on any high-level language for checking if string corresponds the given restriction. You would probably iterate symbols one by one and check if appending next symbol breaks the restriction. 

Now note that you need only two last symbols to do it,  and there are finite number of two-symbols combinations (namely $--, -0,-1,00,01,10,11$, where "$-$" stands for absence of preceding symbol at the very beginning of the string). 

Why wouldn't we use these combinations as automata states? You are left only to add transitions, which are pretty straightforward (e.g. appending $0$ to $11$ transits to $10$, appending $1$ to $00$ transits to the dead state, and so on). Can you finish it now?