Combine Several Spreadsheets into One

Sometimes I have several google sheet file with the same column.
I need to combine all of them to make the summary.
So, this is what I do ...

1. Make sure they have the same column
    All my example have column A to F

2. Copy the sheet's ID, (the random character after =)

3. Put it in a sheet at the master file

4. Call it in a new sheet

    I use: =ImportRange(list!B1,"A1:F") to call all column,
    and will grow whenever my data insert new record.

5. Make a master sheet, and combine all ...
    a. I call all records with no blanks: 
        =FILTER('1st Data'!A2:F,'1st Data'!A2:A<>"")
    b. Combine all filter using {}, and seperate with ;
        ={FILTER('1st Data'!A2:F,'1st Data'!A2:A<>"");
FILTER('2nd Data'!A2:F,'2nd Data'!A2:A<>"")}

6. [optional] Add an auto numbering
    In the first row, I use =ARRAYFORMULA(IF(ISBLANK(B2:B),"",ROW(A2:A)-1))
    to call the number of row filled with data.

See the sample here.