Best approach for creating clock sources please?

Yes, just the answer I was looking for! Spot on. :)

--The main clock source for everything is running at 24MHz
--Create an 8MHz & n8Mhz clock enable
  proc_8MHz : PROCESS (nPowerSettleDelay, M24MHz)
  BEGIN
    IF nPowerSettleDelay='0' THEN
      en_uM8MHz     <= '1';
      en_u_nM8MHz   <= '0';
      Next_State <= State_1;
    ELSIF RISING_EDGE(M24MHz) THEN
      CASE Next_State IS
        WHEN State_1 =>
          Next_State <= State_2;
          en_uM8MHz   <= '1';          --  1
          en_u_nM8MHz <= '0';          --  0
        WHEN State_2 =>
          Next_State <= State_3;
          en_uM8MHz   <= '0';          --  0
          en_u_nM8MHz <= '1';          --  1
        WHEN State_3 =>
          Next_State <= State_1;
          en_uM8MHz   <= '0';          --  0
          en_u_nM8MHz <= '0';          --  0
      END CASE;
    END IF;
  END PROCESS proc_8MHz;
  
  --Do something that is @ 8MHz
  proc_DoSomething_8MHz : PROCESS(M24MHz)
  BEGIN
    IF RISING_EDGE(M24MHz) THEN        
        IF en_uM8MHz THEN
            --do something every @ 8MHz
        END IF;
    END IF;
  END PROCESS proc_DoSomething_8MHz;
  
  --Do something that is @ /8MHz
  proc_DoSomething_n8MHz : PROCESS(M24MHz)
  BEGIN
    IF RISING_EDGE(M24MHz) THEN        
        IF en_u_nM8MHz THEN
            --do something every @ /8MHz
        END IF;
    END IF;
  END PROCESS proc_DoSomething_n8MHz;