Knitted doilies should not be pressed; they really don't look good until you stretch them.  Here's one of mine stretched, pinned and starched.
 
 

I usually stretch my doilies on an old fabric cutting board.  I cover it with a clean white trash bag, and that way I can see through it to line the doily up with the lines on the cutting board.  I use large T-pins to pin it out.  The doily will take a lot of tension on the threads, so don't be afraid to pull one out like it should look.  Start by quartering it, putting the opposing pins in, and then eighth it, and so on until you get all the edge design pinned out.  Some doilies can be pinned either square or circular, so decide ahead of time which you want for yours.  Then spray it well with heavy spray starch, and leave it to dry.  When it's dry, it's ready to use.

This is the Cindy doily from Gloria Penning's book, Knitted Heirlooms, III.  I think you can see that it lays quite flat once it's stretched.  When you get it off the knitting needles, like all doilies, you will have a wad of thread, but stretching it makes all the difference.  This one was knitted with size 10 cotton thread and #2 needles, and it measures about 18" across.  I did find what I think are two mistakes in the instructions for this doily.  I believe on line 67 it should read, "slip the SKP over the K2 tog" as it did back in line 43.  Then the crocheted last round should say, "pick up 4 sts, sc, ch 5, pick up next 2 sts, sc, ch 5."  Anyway, that's how I resolved my problem with it.   This is a very easy doily and lots of fun to make.

This is another heart doily I knitted some years ago.  As I was knitting the pink one, I got to wondering about this one, so I pulled it out to compare them. This one is only about 12" or so across.  I'm not sure right this minute where I got this one.

This is the Clara doily from Gloria Penning's Danish Lace Treasures.  This version isn't exactly like the original.  On row 41, the instructions say you should wind up with 24 stitches in the repeat, and I can't see where you can get more than 21 per repeat as it's written.  As a result, I altered the pattern somewhat.  There is also a typo on the last round of the doily.  Where the instructions say to P34, I believe that should be P4.  At any rate, this is what I wound up with, and  I think it makes an attractive doily.  It measures 15" across made with size 10 cotton thread and #2 needles.  Sorry about the reflection from my chandelier.

BTW, this doily has some K5tog and K3tog moves in it.  So don't be surprised when you find those.  There is also a k7 in one stitch in the last row.  These moves slow the work down, but they can be done.  This doily is an easy one to stretch, as all you need do is pin out the points around it.

(c) 2001 by Glynda Black.  All Rights Reserved.