Step 3: Complete the Mould
Because the lego is hollow it will want to float up, so have something to weigh it down. I used some erasers. Try to keep at least 3-4mm between each mould space, otherwise the mould can tear.
If you have bubbles in the silicone, blow on them with hot breath - it will pull the bubbles out. Don't use a hairdryer - too powerful.