I am doing a 2 tiered birthday cake for my daughter. There will only be 20 people but I want to do at least 2 tiers to look right. I am wondering what will look better, a 6" cake stacked on an 8" or a 6" cake on a 10" cake. I know sometimes cakes look silly when the sizing is off and since I have a small group to serve, the 6" cake is just extra. Thanks for all input!

6/9 also looks good.

Depends on the design. I've done both and I think both look fine.

i agree with both above. it all depends on design, you can see a couple of my examples.

these are 6/9
http://cakecentral.com/modules.php?name=gallery&file=displayimage&pid=1628878
http://cakecentral.com/modules.php?name=gallery&file=displayimage&pid=1397579

this one is 6/8
http://cakecentral.com/modules.php?name=gallery&file=displayimage&pid=600623

i agree, either are fine, just depends on the designs. do you need an extra inch in which to place decorations like bows, flowers, etc? if so go with the 6 and 10. sometimes with the 6 and 8 there isn't much room except for the border where the two meet.

In my opinion, 6 on top of a 10 looks better because you get a better view of the different sizes of the cake.