I was having the hardest time with modes until I started doing this. I don't know why this is easier for me but it is. Maybe this will help someone.
Try playing your major scale like so:
E -I-----I-----I-----I-----I-----I---
B -I-----I-----I--7--I--8--I-----I---
G -I--4--I-----I--5--I-----I--6--I---
D -I--1--I-----I--2--I-----I--3--I---
A -I-----I-----I-----I-----I-----I---
E -I-----I-----I-----I-----I-----I---
From there impliment the following changes:
1. Ionian - 1 2 3 4 5 6 7 8
2. Dorian - 1 2 b3 4 5 6 b7 8
3. Phrygian - 1 b2 b3 4 5 b6 b7 8
4. Lydian - 1 2 3 #4 5 6 7 8
5. Mixolydian - 1 2 3 4 5 6 b7 8
6. Aeolian - 1 2 b3 4 5 b6 b7 8
7. Locrian - 1 b2 b3 4 b5 b6 b7 8
Try playing your major scale like so:
E -I-----I-----I-----I-----I-----I---
B -I-----I-----I--7--I--8--I-----I---
G -I--4--I-----I--5--I-----I--6--I---
D -I--1--I-----I--2--I-----I--3--I---
A -I-----I-----I-----I-----I-----I---
E -I-----I-----I-----I-----I-----I---
From there impliment the following changes:
1. Ionian - 1 2 3 4 5 6 7 8
2. Dorian - 1 2 b3 4 5 6 b7 8
3. Phrygian - 1 b2 b3 4 5 b6 b7 8
4. Lydian - 1 2 3 #4 5 6 7 8
5. Mixolydian - 1 2 3 4 5 6 b7 8
6. Aeolian - 1 2 b3 4 5 b6 b7 8
7. Locrian - 1 b2 b3 4 b5 b6 b7 8