Try to start modeling your problem as a state machine. Separate the combinational and the sequential part in two state machines. The flow becomes quite similar

Try to start modeling your problem as a state machine. Separate the combinational and the sequential part in two state machines. The flow becomes quite similar to regular embedded system software (that can be programmed using state machine pattern as well). Say e.g: state read_input => reg_a <= input next_state <= multiply_input_by_10 state multiply_input_by_10 => reg_b <= reg_a * 10 next_state <= finish state send_to_output => finish_reg <= '1' and then parallel to that you would have finish_wire <= finish_reg value_wire <= reg_b or something like that, sorry for the bad example but definitely use state machines