The most important thing to do when
preparing a talk is remember you know
way more about your subject than anyone
else. So you should never assume
knowledge of the audience and you should
always pitch your talk at a level where
you are sure that everyone will
understand whether they're an expert or
not. In terms of preparation - practice is
everything, so make your talk well in
advance, run through it multiple times
and if possible present it to people who
know nothing at all about what you work
on because they're the audience you're
trying to capture. If you can explain it
to your sister or to your best friend
who works on a completely different
subject then you're hitting it about the
right level. Practice also helps you with
one of the most important things when
actually presenting the talk which is
eye contact with the audience. No one
wants to look at the back of your head,
no one wants to watch you reading
the slide. They want to look you in the
eye as you're giving a talk. When you're
preparing slides keep them as simple and
as clean as possible.
Design is everything. Animations may look
cool on your laptop but you should only
use them if they are really needed to
accentuate the point that you're making.
You don't want to distract the listeners
from the words that you're saying so by
all means when you're making slides
start out by putting a lot of text but
then as you develop your talk and refine
it you should be trimming that text out
so that you just have the main salient
bullet points. If you have thousands of
points on a dot plot but you only care
about 20 that have gone up or down
significantly
put a big circle around those 20, put an
arrow around those 20. Keeping time is
obviously a critical thing. I use as a
rule of thumb roughly one slide per
minute of talk. You might be slightly
longer or shorter than that but if
you're giving a 10 minute talk more than
10 slides is almost certainly too long. Try to minimise stress before you give
your talk, so get your slides to the a/v
technicians well in advance of your
session, make sure that they are
projecting and run through okay so that
you just don't have to worry about that -
that's all taken care of. If you get the
chance go up to the podium before your
session starts and familiarise yourself
with the equipment - what
button to press to change the slides
what button to press to make the laser
pointer work. Use your laser pointer
sparingly and just point out critical
pieces of data to illustrate the point
that you're making. Remember that the AV technicians are here to help you so if
you have a technical issue, if
something's not working, stay calm. First
just try and calmly do it again and then
if you need help if you need their
attention
you can do this subtly, calmly and
someone will do something to help you. You should be aware of your audience
while you're giving a talk. So sometimes
you can be deep in one section of the
slide and if you're doing your job
properly and looking around the audience
you can tell whether people are with
you or not with you, so don't be afraid
to adapt and make sure that everything
is clearly across. People want to hear
excitement in scientific talks, so don't
be afraid to get wound up in the data.
The more passion and the more
information that you give, the more
likely people are to remember your talk
at the end of the day - remember that
crazy guy who waved his arms around?!
That's fine as long as you're
communicating your science in a way that
everyone can understand put every bit of
passion and interest in it that you can.
Answering questions after talks can be
one of the most intimidating things
about giving a talk especially in a big
conference with lots of people. One of
the most important things to remember is
make sure you let the questioner finish
their question before you answer. Make
sure you think about what question
they're actually asking and not just
present them with some predigested
answer and do your best to answer the
question directly. 
No one likes politicians who never
actually answer the question that
they're given. Timing is everything - you
don't want to overstay your welcome so
make sure you're aware of the traffic
light system in front of you and the
timing and if it starts flashing yellow
that's the sign that you need to start
wrapping up, not that you need to go
through all of the slides that you
still have left at breakneck speed but
you really need to start wrapping up
before it hits red and you're forced off
the stage. If you've prepared well and
practiced it shouldn't be a problem but
always be aware of how much time you
have left and be prepared to skip a few
slides to get to the end.
