Probably there is more than one way, maybe check out some of the techniques in representation or dimensioning...however; in a pinch, you could even use the Buffer tool and achieve some impressive results if you don't mind creating a 'spare' or temp fc. If in your 'scratch' gdb, then no big deal. Hint: For those features clustered together you may want to 'dissolve' overlapping features - and the buffer tool will optionally do this too (or pick and choose, modifying the buffer output yourself to merge, move, etc., in your edit session).