Related Clues:

• 'Not too hard now' ... or a homophonic hint to 17-, 23-, 35- and 48-Across
• Be careful playing with seaside toy
• "___, two, three, four!" (marching syllables)
• I see today's problem! Take your time!
• One, to a drill sergeant
• Military cadence syllable
• "Careful now" ... and a hint to what's hidden in 17-, 27- and 46-Across
• 'Careful now' ... and a hint to what's hidden in 17-, 27- and 46-Across
• Preceder of 'two, three, four'
• Be vigilant -- this could make synchronisation difficult!
• Simple to make site changes: take it gently
• March opening
• Drill syllable
• “Careful!”
• Not strict diet, so anyhow take your time