Diana's taffeta and lace dress, with a 25-foot-long train, was designed by Elizabeth Emanuel. (AFP - Getty Images)

The designer of Diana’s iconic wedding dress has some solid advice for Kate Middleton: If you want to keep the gown a secret, strict security measures are key.

Elizabeth Emanuel reminisced about her experience designing for a royal wedding, which led to an immense media curiosity that she wasn’t necessarily ready for. In fact, Emanuel even locked the fluffy white dress in a safe every night to fend off reporters who snooped outside her doorstep and rummaged through trash bins.

"There was so much media interest, all wanting to know what the dress was going to look like and of course we couldn't say anything," Elizabeth Emanuel told Reuters this week. "We used to leave bits of different colored threads and things to put them on the wrong track and we had to put blinds up so that people couldn't peer through the windows… And we even had a spare dress hanging up just in case somebody did discover the secret."

As for fresh-faced Kate, Emanuel is confident the princess-to-be already has a leg up on Diana, who was just a shy 20-year-old when she was introduced to the royal limelight.

"With Diana she was very young, when we were introduced to her and fashion was not one of her big interests so she didn't really have her own sense of style," Emanuel said. "But Kate Middleton does. She's worked in fashion. She knows what suits her so she's probably got a very firm idea of what kind of dress she wants."

Although Bruce Oldfield is rumored to be designing Kate’s wedding gown, that didn’t stop Emanuel from sharing her opinions on Kate’s dress, namely that it should be “more subdued” and “current” than Diana’s very '80s (an understatement?) voluminous gown with bulbous sleeves, 25-foot-train and tiara.

But no matter what Kate does wear, Emanuel agrees it will be an exciting, celebrated event — tiara or not:  “We're going to see what Britain does really well — a royal wedding."

Related: The wedding of Charles and Diana
Kate's dress? British press backs Oldfield
Designers sketch Kate’s wedding gown