From experience the best advice from above would be to rely less on the chart and learn to trust your planning. Planning and preparation etc. is the key to good navigation.
If you think your way through the flight and carefully prepare you chart and PLog then this will reduce workload inthe cockpit.
An aircraft flown out of balance ( wings not level) and not in trim (fluctuating around an altitude) might be held on constant heading but will not acheive expected airspeed. Conversely, if you get the performance right and your flight planning is sound then you can rely on heading and time as a means to get you where you want to be.
I use 1/4, 1/2 and 3/4 marks on each leg with ETAs for each. Based on the first 1/4 I will have a rough idea of what my TE is likley to be by halfway and double this to get my correction angle to apply. Rather than making lots of small corrections I favour the fewer and bigger approach. At least that way you get a better fix on what the wind is actually doing over a longer period of time - useful if you need to plan a diversion or emergency landing.
Don't creep along you route on the chart. Remember, you are flying the aircraft in a straight line ( if you maintain heading etc.) and so every 10 minutes or so should be enough to check you actual position against expected progress. You are looking for trend and, by adopting the 1 in 60 rule, should be able to anticipate where you next waypoint is likley to be realtive to your planned track, based on the previous fix. Sometimes, by trying to follow a line feature on a chart, you can get lost simply by missing a motorwayor railway interchange.
Practice and get you instructor to set you some challenges. Turning points need not be many miles apart but should be sufficently well spaced that you can use the intervening flight time to do some mental arithmetic and adjust your ETAs etc. Make sure he give you at least two diversions on each navex and learn as many rules of thumbs as you can - its all pretty basic geometry. Flying around cloud then returning to your previous track is also good practice.
Finally, I would advocate the use of VOR/ADF equipment to keep yourself appraised of position - always easy when you know where you should be but not when you are truly lost. Do not use a sole means of navigation!
There are lots of ways to get caught out and perhaps the simplest is not synchronising you DI with compass. Remember, make sure that your wings are level and that you are not climbing or descending, in balance and in trim.
Time, map, ground is the addage that I was taught and it has always worked for me. A good ( digital) stopwatch is easier to navigate with although you will need a proper clock for IR. Once you know where your meant to be its much easier confirming you position by finding the chart features on the ground than vice versa. All motorways look the same as do many of the junctions. But, each is unique when you start comparing other notable features - I challenge you to do that from ground to chart.
There are many tips and tricks but find what works for you and hone your skills with practice. I used to clutter my charts with all sorts of extraneous information but I have found simple is best and if you plan well the infromation always comes readily to hand.