The first step to producing convincing baroque continuo keyboard parts is undestanding figured bass. Figured bass is a shorthand: composers wrote a bassline plus as few figures as can convey the harmonic gist.
refer to the table below and fill in the missing figures (you need to do this because figured bass is a short hand). 6, for example, becomes 6 / 3
for each figure count the relevant number of notes up from the written bass note (the bass note is counted as 1) and write it on the stave above
if a figure has a flat or sharp insert one before the relevant note (remember that 4 does not necessarily mean a perfect fourth - a fourth above F in C major is augmented unless it is followed by a sign)