Don't necessarily blame it on the tension, I did this a lot when I first sewed something. I talked to women at Joann and they told me that two other things cause this, especially when two different materials are involved.

First is feeding the material into the machine, don't pull the material through, allow the machine to dictate the speed, but hold the material taut so they feed through together.

The second problem is when one material is slicker than the other, it may be sliding through at a different speed. The suggestion for this was pinning the two materials together. I found this tedious, and kept forgetting to remove the needle causing the machine needle to hit the pinning needle, dulling the machine needle. I switched to taping the two together. There is a sewing tape that dissolves when it is washed, it does a great job of holding the two pieces together while sewing.

Still don't have the guts to attempt a quilt.
Life should not be a journey to the grave with the intent of arriving safely in a well preserved body, but to skid in broadside, thoroughly used up, worn out, and loudly proclaiming Wow! What a Ride!