New to BBT charting

Carol • Mother to 2 lovely kids Liam age 9 and Penelope (Penny) age 1 , also expecting baby number 3 due September 2016 ! 💙💗
Ok so I started charting today I'm on month 3 TTC 
​Thought if chart to make the most of this app and <a href="https://play.google.com/store/apps/details?id=com.glow.android">track fertility</a> more , I also OPK.
​I'm in the UK so it's degrees centigrade here on my thermometer .
​Any charting tips for a newbie? 
​I'm on CD 6 today . Am I right to think that a temp reduction is bad after ovulation and means AF is on the way? 
​And a temp increase after ovulation is good ? 
​Any tips from pros most welcome ! 
​Carol x