remember key trigonometric identities that can help you in intergration

sin^2 + cos^2 = 1
1 + tan^2 = sec^2
1 + cot^2 + csc^2

Also you need to know the derivatives of trig functions

sinx ..... derivative    cosx
cosx.....  derivative  -sinx
tanx ......derivative   sec^2 x
cotx ....  derivative  -csc^2 x
secx....   derivative   tanxsecx
cscx ....  derivative   -cotxcscx

the trig identities come in handy to do substitutions to obtain antiderivatives.