Say and Sign before you do
Here's the thing. If your toddler cries at your feet and you just pick them up, then they learn that 'crying at mums feet gets me picked up', so they'll keep communicating like that. If instead you model for them the words and the sign they could use, then in the future they're more likely to speak or sign to you to tell you exactly what they want. Magic!
This doesn't mean you become some cruel demanding mother who doesn't pick their upset child up. It just means that A SECOND before you do, you model for them how they could communicate their needs to you in another way. If you pause an extra second after that, they may imitate you. Over time with consistent modelling, your little one is going to shift from crying to be picked up to ASKING to be picked up.
THIS IS A COMMUNICATION TEMPTATION.
If you model and then pause, you're tempting your little one to communicate because they really want to be picked up so they're motivated to imitate you.
REMEMBER: your little one can sign/gesture months before they can talk because hand and arm movements develop before the muscles required to make speech sounds. So if you sign as well as say "up" it's likely that they'll learn to imitate the arm movements first. The word will come later.