Plan each of the two phases within a weekly schedule. General guidelines to consider:
Skills/TechniquesIn the general phase you want to assess the abilities of your players as individuals and as a team. You can have tryouts for spots on the team as well as for positions within the team. In the specific phase you want to develop, refine the techniques and teach players to use them in combination. For example, after they have perfected dribbling skills and shooting skills, you want them to perfect a precise, powerful shot after a successful dribble.
Tactics/StrategiesIn the general preparation, you want to assess your players and decide the style, system of play and position for each player, including a depth chart (i.e. who is best for a position, 2nd in line , 3rd). You want to consider whatever knowledge you have about your opponents and the relative strength of your team in addition to your personnel when you design your team's style and system. In the specific preparation, you want to train your team's system, both in units (goalie, defense, midfield, attack) as well as in various combinations (defenders and midfielders, midfielders and forwards, goalie and defenders) leading to the full team functioning well together.
Mental TrainingIn the general phase, you want to introduce emotional controls for individuals (relaxation, stretching, breathing techniques) and attentional control (concentration - visualization is a candidate). You need to assess your players and see if there are any individuals or circumstantial barriers to team harmony. Schedule one on one conversations with players to get to know them and for them to get to know and trust you. Develop strategies for managing each individual (communication, motivation, etc.) and for the team in total so you can prepare them individually for peak performance. In other words, find out what makes each player "tick" and make them "tick".
In the specific phase, start applying emotional and concentration control as part of pre-practice and pre-game routine for your exhibition games. Towards the end of the specific phase, set team goals for the season and have a team bonding event.
Physical PreparationIn the general phase, build an aerobic base (10 km runs, playing beach soccer in the sand, etc.), develop flexibility where needed (particularly goalkeepers) and introduce concepts of proper athletic nutrition. In the specific phase, complete aerobic training by developing aerobic power (long time at high intensity), start developing leg strength (lunges, weights) and train anaerobically (sprint, interval). Insist on proper nutrition throughout the week. Use measurements of time, distance and weight to chart player progress.
Peaking IndexIn the general phase, your work volume should be medium and your intensity should be low. In the specific phase, keep volume at medium, increase intensity to medium with the last two weeks at high.
ConsiderationsThe suggestion would be a practice to game ratio of 3:1. For example, practice on Monday, Wednesday, Friday and play a full field game on Saturday. Do most of the aerobic work on Monday and Wednesday and more of the tactical and skill work (with lower aerobic content) on Friday. Keep this ratio going right through the season.
As you move into the specific phase increase the intensity, i.e. be physically, mentally, technically and tactically more demanding. For example, demand full attention and concentration, execute drills faster and better with more precision. Increase the level of opposition in exhibition games (perhaps play a senior men's team).
Once the season starts, you need to see how your team performs and design practice plans based on game analysis in combination with your overall goals and systems.