In every MMO I've ever played I've done some dps as a healer. My secret? Macros. I have my dps spells set to [shift] numbers, every dps spell is a 3 part macro"
/macroicon combust
/ac "Combust" <t>
/ac "Combust" <tt>
/ac "Combust" <ft>
<t> is target, <tt> is Target's Target (great for healers so you can still keep your party targeted), <FT> is Focus Target (I used this mostly in WOD or any boss that you need their health bar/cast bar visable for inc damage indications.)
This macro also makes it really easy to solo as it tries to cast on <t> first, then <tt>. with <ft> as last ditch target. Every dps sepll on AST, WHM, and Arcanist is written this way (with smn pet commands added at bottom for added help)
All you need to remember then? Turn of Clerics!