If conditions are right do a fancy step but there is no need to over do it. One done really well will be more fun and make a better impression than any number done poorly. This will leave your partner with a good or at least neutral feeling. Which is much better than a bad feeling. Over time you will acquire enough basic steps and fancy steps to make a dance interesting to a wide variety of partners.
Simple perfection is so much better than clumsy complexity.
Leaders, do not start with your most complicated patterns - start dancing basics. If a follower misses a lead or falls behind, you can just keep the beat for an extra few beats until the follower gets her balance back and is grounded again. Followers should come out on time and be ready to accept my Lead, but the considerate leader will notice if his follower gets off time and will wait for her to catch up, skipping a beat or two if necessary. If the follower is not responsive to a lead for a particular figure, do a different one and show the person that figure after the dance. A poor leader will force the follower through the figure.