It all depends where you're playing it, and how many times you want to play the mode. Playing a mode through once would be going from one note to that same note an octave up (let's say an A). For the A Ionian scale, you'd be playing the notes A, B, C#, D, E, F#, G#, A. In first position, you could play that like this:

e------------------------------
b------------------------------
g---------------------1--2-----
d-----------0--2--4------------
a--0--2--4---------------------
e------------------------------

Or you could play it in fourth position, like this:

e------------------------------
b------------------------------
g------------------------------
d-----------------4--6--7------
a--------4--5--7---------------
e--5--7------------------------

Now you could also go through the mode twice, so that you start at A and end at A two octaves up. In first position, you'd have something like this:

e------------------------------------0--2--4--5
b------------------------------2--3------------
g---------------------1--2--4------------------
d-----------0--2--4----------------------------
a--0--2--4-------------------------------------
e----------------------------------------------

That's an easy one to figure out fingering for; just use the same finger as the fret number (except for the last note, in which case just slide your pinky up from the 4th fret to the 5th).

I hope that answers what you're asking. I also hope I didn't screw that up somewhere, as my knowledge of theory is pretty rudimentary.