Using a stop loss of 3% seems pretty arbitrary, unless I guess your stats support that. Consider using price action, setup pattern and technical support-resistance levels/areas to set your stops instead. Maybe it's not so much about "timing" as it is about your stop selection.
Also, consider using MAs for timing. If you determine which MA the trend appears to be most closely conforming to (i.e, "riding"), then in general, the best entries occur when price is at or near the "controlling" MA. The MA should also be sloped in the direction of the trend you seek to capture, and should be positioned relative to each other ("stacked") appropriately.
Finally re: timing -- avoid entering when the trend is "extended." On your primary trade timeframe, one way to help assess this is to generally observe how many consecutive green or red bars have occurred prior to your entry... as well as their relative sizes and corresponding volume. If you're taking entries that are consistently after say, ~ 3 or more average-sized bars have occurred in your direction... and/or if the recent bars are large ("wide range")... and especially if the wide range bars (WRBs) are associated with exceptionally high volume (relative to prior volume) -- then it's likely that the trend is temporarily extended/exhausted, and likely to reverse short-term. For pullback entries, you'd generally prefer to see a brief series of countertrend bars with correspondingly low/decreasing volume, and no extreme WRBs or unusually high volume.
Maybe try looking at your entries relative to the two prior criteria I mentioned, and see how they compare. Also, look at where/when the "ideal" entries occurred (in perfect hindsight), and also compare them to those criteria. Perhaps you'll notice some patterns or tendencies.
Good luck!
